Wireless communication device, wireless communication method, and program

ABSTRACT

A wireless communication device, a wireless communication method, and a program capable of contributing to improvement of wireless communication technology related to IDMA. The wireless communication device includes: a wireless communication unit that performs wireless communication using interleave division multiple access (IDMA) with another wireless communication device; and a controller that controls an interleave length in an interleave process for IDMA by the wireless communication unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/327,613, filed on Jan. 19, 2017, which is a National Stage Entry ofInternational Patent Application No. PCT/JP2015/069945, filed on Jul.10, 2015, and claims priority to Japanese Patent Application2014-195261, filed in the Japanese Patent Office on Sep. 25, 2014, theentire contents of which is hereby incorporated herein by reference inits entirety.

TECHNICAL FIELD

The present disclosure relates to a wireless communication device, awireless communication method, and a program.

BACKGROUND ART

Recent wireless communication environment shave faced an abrupt datatraffic increase problem. Accordingly, interleave division multipleaccess (IDMA) has drawn attention as one of radio access technologies(RAT) of fifth generation mobile communication systems (5G). Forexample, a technology for reducing inter-cell interference or intra-cellinterference according to the principle of IDMA is being developed as atechnology related to IDMA.

For example, Patent Literature 1 below discloses a technology throughwhich a user in a cell cancels inter-cell interference by applyingdifferent interleave patterns while maintaining orthogonality using timedivision multiple access (TDMA), frequency division multiple access(FDMA) or the like and performs multi-user detection (MUD).

Furthermore, Patent Literature 2 below discloses a technology forapplying different interleaves to a plurality of signals multiplexed tothe same spatial stream in multi-input multi-output (MIMO) andmulti-antenna spatial multiplexing.

CITATION LIST Patent Literature

Patent Literature 1: JP 2004-194288A

Patent Literature 2: JP 2009-55228A

DISCLOSURE OF INVENTION Technical Problem

However, technical fields related to IDMA require further performanceimprovement. Accordingly, the present disclosure proposes a novel andimproved wireless communication device, wireless communication methodand program capable of contributing to improvement of wirelesscommunication technology related to IDMA.

Solution to Problem

According to the present disclosure, there is provided a wirelesscommunication device including: a wireless communication unit thatperforms wireless communication using interleave division multipleaccess (IDMA) with another wireless communication device; and acontroller that controls an interleave length in an interleave processfor IDMA by the wireless communication unit.

According to the present disclosure, there is provided a wirelesscommunication device including: a wireless communication unit thatperforms wireless communication using IDMA with another wirelesscommunication device; and a controller that controls the wirelesscommunication unit to perform a deinterleave process depending on aninterleave length used for an interleave process for IDMA by the otherwireless communication device.

According to the present disclosure, there is provided a wirelesscommunication method including: performing wireless communication usingIDMA with another wireless communication device; and controlling aninterleave length in an interleave process for IDMA through a processor.

According to the present disclosure, there is provided a wirelesscommunication method including: performing wireless communication usingIDMA with another wireless communication device; and controlling adeinterleave process depending on an interleave length used for aninterleave process for IDMA by the other wireless communication deviceto be performed through a processor.

According to the present disclosure, there is provided a program forcausing a computer to function as: a wireless communication unit thatperforms wireless communication using IDMA with another wirelesscommunication device; and a controller that controls an interleavelength in an interleave process for IDMA by the wireless communicationunit.

According to the present disclosure, there is provided a program forcausing a computer to function as: a wireless communication unit thatperforms wireless communication using IDMA with another wirelesscommunication device; and a controller that controls the wirelesscommunication unit to perform a deinterleave process depending on aninterleave length used for an interleave process for IDMA by the otherwireless communication device.

Advantageous Effects of Invention

According to the present disclosure described above, it is possible tocontribute to improvement of wireless communication technology relatedto IDMA. Note that the effects described above are not necessarilylimitative. With or in the place of the above effects, there may beachieved any one of the effects described in this specification or othereffects that may be grasped from this specification.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an explanatory diagram of a technology related to IDMA

FIG. 2 is an explanatory diagram of a technology related to IDMA

FIG. 3 is an explanatory diagram of a technology related to IDMA

FIG. 4 is an explanatory diagram of a technology related to IDMA

FIG. 5 is an explanatory diagram of an overview of a wirelesscommunication system according to an embodiment of the presentdisclosure.

FIG. 6 is a block diagram illustrating an example of a logicalconfiguration of a transmitting station according to the presentembodiment.

FIG. 7 is a block diagram illustrating an example of a logicalconfiguration of a receiving station according to the presentembodiment.

FIG. 8 is a sequence diagram illustrating an example of the flow of anallocation process executed in the communication system according to theembodiment.

FIG. 9 is a sequence diagram illustrating an example of the flow of awireless communication process executed in the wireless communicationsystem according to the present embodiment.

FIG. 10 is a block diagram illustrating an example of a logicalconfiguration of a wireless communication unit of the transmittingstation according to the present embodiment.

FIG. 11 is a flowchart illustrating an example of the flow of a paddingprocess executed in the transmitting station according to the presentembodiment.

FIG. 12 is a flowchart illustrating an example of the flow of a paddingprocess executed in the transmitting station according to the presentembodiment.

FIG. 13 is a flowchart illustrating an example of the flow of aninterleave length decision process executed in the transmitting stationaccording to the present embodiment.

FIG. 14 is a flowchart illustrating an example of the flow of aninterleave length decision process executed in the transmitting stationaccording to the present embodiment.

FIG. 15 is an explanatory diagram of an interleave pattern controlmethod according to the present embodiment.

FIG. 16 is a block diagram illustrating an internal configuration of aCW interleaver according to the present embodiment.

FIG. 17 is a block diagram illustrating an internal configuration of aCW interleaver according to the present embodiment.

FIG. 18 is a block diagram illustrating an internal configuration of aCW interleaver according to the present embodiment.

FIG. 19 is a flowchart illustrating an example of the flow of aninterleave length decision process executed in the transmitting stationaccording to the present embodiment.

FIG. 20 is a flowchart illustrating an example of the flow of a HARQtype determination process executed in the transmitting stationaccording to the present embodiment.

FIG. 21 is a flowchart illustrating an example of the flow of aretransmission type decision process executed in the transmittingstation according to the present embodiment.

FIG. 22 is a flowchart illustrating an example of the flow of a processof switching between execution and non-execution of an interleaveprocess performed in the transmitting station according to the presentembodiment.

FIG. 23 is a flowchart illustrating an example of the flow of a processof switching between execution and non-execution of an interleaveprocess performed in the transmitting station according to the presentembodiment.

FIG. 24 is a flowchart illustrating an example of the flow of adeinterleave setting control process executed in the transmittingstation according to the present embodiment.

FIG. 25 is a block diagram illustrating an example of a logicalconfiguration of a wireless communication unit of the transmittingstation according to the present embodiment.

FIG. 26 is a block diagram illustrating an example of a logicalconfiguration of a wireless communication unit of the transmittingstation according to the present embodiment.

FIG. 27 is an explanatory diagram of a resource grid of OFDMA.

FIG. 28 is a block diagram illustrating an example of a logicalconfiguration of a wireless communication unit of the receiving stationaccording to the present embodiment.

FIG. 29 is an explanatory diagram illustrating an example of the flow ofa decoding process through the receiving station according to thepresent embodiment.

FIG. 30 is an explanatory diagram illustrating an example of the flow ofa decoding process through the receiving station according to thepresent embodiment.

FIG. 31 is a block diagram illustrating an example of a logicalconfiguration of a CW decoder according to the present embodiment.

FIG. 32 is an explanatory diagram illustrating an example of the flow ofa decoding process through the receiving station according to thepresent embodiment.

FIG. 33 is an explanatory diagram illustrating an example of the flow ofa decoding process through the receiving station according to thepresent embodiment.

FIG. 34 is an explanatory diagram illustrating an example of the flow ofa decoding process through the receiving station according to thepresent embodiment.

FIG. 35 is an explanatory diagram illustrating an example of the flow ofa decoding process through the receiving station according to thepresent embodiment.

FIG. 36 is a flowchart illustrating an example of the flow of adeinterleave length decision process executed in the receiving stationaccording to the present embodiment.

FIG. 37 is a flowchart illustrating an example of the flow of adeinterleave length decision process executed in the receiving stationaccording to the present embodiment.

FIG. 38 is a flowchart illustrating an example of the flow of adeinterleave length decision process executed in the receiving stationaccording to the present embodiment.

FIG. 39 is a block diagram illustrating an example of a schematicconfiguration of a server.

FIG. 40 is a block diagram illustrating a first example of a schematicconfiguration of an eNB.

FIG. 41 is a block diagram illustrating a second example of theschematic configuration of the eNB.

FIG. 42 is a block diagram illustrating an example of a schematicconfiguration of a smartphone.

FIG. 43 is a block diagram illustrating an example of a schematicconfiguration of a car navigation device.

MODE(S) FOR CARRYING OUT THE INVENTION

Hereinafter, (a) preferred embodiment(s) of the present disclosure willbe described in detail with reference to the appended drawings. In thisspecification and the appended drawings, structural elements that havesubstantially the same function and structure are denoted with the samereference numerals, and repeated explanation of these structuralelements is omitted.

Also, in this specification and the appended drawings, elements havingsubstantially the same function and structure may in some cases bedistinguished by different letters appended to the same sign. Forexample, multiple elements having substantially the same function andstructure are distinguished as transmitting stations 100A, 100B, and100C, as appropriate. On the other hand, when not particularlydistinguishing each of multiple elements having substantially the samefunction and structure, only the same sign will be given. For example,the transmitting stations 100A, 100B, and 100C will be simply designatedas the transmitting station 100 when not being particularlydistinguished.

A description will be given in the following order.

1. Introduction

1-1. IDMA

1-2. Wireless communication system

2. Examples of configurations

2-1. Example of configuration of transmitting station

2-2. Example of configuration of receiving station

2-3 Example of configuration of communication control device

3. Example of operation process

4. Details of functions

4-1. Processing of physical layer in transmitting station

4-2. Interleave setting

4-3. Interleave setting related to retransmission

4-4. Combination with other multiplexing methods or other multipleaccess methods

4-5. Processing of physical layer in receiving station

4-6. Deinterleave setting

4-7. Control information

5. Application examples

6. Conclusion

INTRODUCTION [1-1. IDMA]

First, a technology related to IDMA will now be described with referenceto FIGS. 1 to 4. FIGS. 1 to 4 are explanatory diagrams of the technologyrelated to IDMA.

Non-orthogonal multiple access has drawn attention as a 5G radio accesstechnology following Long Term Evolution (LTE)/LTE-Advanced (LTE-A).

In orthogonal frequency division multiple access (OFDMA) orsingle-carrier FDMA (SC-FDMA) employed in LTE, radio resources areallocated such that they do not overlap between user equipments in acell. Radio resources are frequency or time resources for wirelesscommunication and there are various types of radio resources, such as aresource block, a subframe, a resource element and the like. Such radioaccess technology for allocating radio resources without overlap is alsocalled orthogonal multiple access.

FIG. 1 illustrates an example of radio resource allocation in orthogonalmultiple access. In FIG. 1, the horizontal axis indicates frequency, andradio resources allocated to users are represented in different colorsfor the respective users. As illustrated in FIG. 1, different resourceblocks (RBs) in the frequency direction may be allocated to users, forexample, in orthogonal multiple access.

On the other hand, in non-orthogonal multiple access, radio resourcesare allocated in such a manner that at least part of the radio resourcesoverlap between user equipments in a cell. When non-orthogonal multipleaccess is employed, signals transmitted and received by user equipmentsin a cell may interfere with each other in a radio space. However, areceiving side may acquire information of each user through apredetermined decoding process. In addition, it is theoretically knownthat non-orthogonal multiple access can achieve higher communicationcapacity (or cell communication capacity) than orthogonal multipleaccess when appropriate radio resource allocation is realized.

FIG. 2 illustrates an example of radio resource allocation innon-orthogonal multiple access. In FIG. 2, the horizontal axis indicatesfrequency, and radio resources allocated to users are represented indifferent colors for the respective users. As illustrated in FIG. 2,resource blocks (RBs) overlapping in the frequency direction may beallocated to users, for example, in non-orthogonal multiple access.

IDMA is one example of radio access technologies classified asnon-orthogonal multiple access. In IDMA, an interleave pattern used fora device at a transmitting side to interleave a transmission signal inorder to identify a user signal is differently allocated to each user.Then, a device at a receiving side separately decodes user signals usingdeinterleave patterns corresponding to interleave patterns allocated torespective users. IDMA has the advantage of a low signal processing loadon a device at a transmitting side. This advantage is regarded asimportant, particularly in uplink (UL) from a user equipment to an eNB.

FIG. 3 illustrates an example of a basic configuration of a transmittingstation 10 performing wireless communication using IDMA. As illustratedin FIG. 3, the transmitting station 10 includes an error correctioncoding circuit 11, an interleaver (πi) 12, a digital modulation circuit13 and a radio frequency (RF) circuit 14. The error correction codingcircuit 11 error-optimal-codes an information bit string of a user i.The interleaver (πi) 12 is an interleaver for which interleave settingfor the user i has been performed and interleaves theerror-correction-coded information bit string. The digital modulationcircuit 13 digitally modulates the interleaved information bit string.The RF circuit 14 performs various signal processes on the digitallymodulated signal and transmits a wireless signal via an antenna.Interleave setting is setting related to at least one of an interleavepattern or an interleave length (interleave size).

FIG. 4 illustrates an example of a basic configuration of a receivingstation 20 performing wireless communication using IDMA. As illustratedin FIG. 4, the receiving station 20 includes an RF circuit 21, a signalseparation circuit 22 and decoding circuits 23. The RF circuit 21performs various signal processes on a wireless signal received throughan antenna and outputs the signal to the signal separation circuit 22.The signal separation circuit 22 has a function of separating acomposite signal obtained by synthesizing signals from users intosignals for the respective users and outputs the separated user signalsto corresponding decoding circuits 23. For example, the decoding circuit23 i includes a deinterleaver (π_(i) ⁻¹) 24 for which deinterleavesetting for the user i has been performed, an error correction decodingcircuit 25 and an interleaver (π_(i)) 26 for which interleave settingfor the user i has been performed. The decoding circuit 23 i receives auser signal from the user i and performs a deinterleave process throughthe deinterleaver (π_(i) ⁻¹) 24 and decoding through the errorcorrection decoding circuit 25. The decoding circuit 23 i outputs theuser signal as an information bit string of the user i when the usersignal has been correctly decoded. In addition, the decoding circuit 23i interleaves the decoded signal through the interleaver (π_(i)) 26 andreturns the signal to the signal separation circuit 22 as a user signalfor the user i. Such user signal return is performed for all usersignals. The signal separation circuit 22 re-separates the returned usersignals and re-outputs the separated user signals to the decodingcircuits 23. The receiving station 20 decodes the user signals byrepeating the signal processes in the signal separation circuit 22 andthe decoding circuits 23.

[1-2. Wireless Communication System] (1-2-1. Overall Configuration)

FIG. 5 is an explanatory diagram of an overview of a wirelesscommunication system according to an embodiment of the presentdisclosure. As illustrated in FIG. 5, the wireless communication system1 according to the present embodiment includes a transmitting station10), a receiving station 200), a communication control device 300 and acore network 500.

The transmitting station 100 is a device that transmits data to thereceiving station 200. For example, the transmitting station 100 is anevolutional Node B (eNB) or an access point in a cellular system. Inaddition, the receiving station 200 is a wireless communication devicethat receives data transmitted from the transmitting station 100. Forexample, the receiving station 200 is a user equipment (UE) in thecellular system.

In the example illustrated in FIG. 5, a transmitting station 100A is aneNB that provides wireless communication services to one or moreterminal devices located inside of a cell 400. In addition, receivingstations 200A and 200B are UEs provided with the wireless communicationservices by the eNB. For example, the eNB 100A may transmit data to theUEs 200A and 200B. The eNB 100A is connected to the core network 500.The core network 500 is connected to a packet data network (PDN) via agateway device. The cell 400 may be operated according to any wirelesscommunication system such as Long Term Evolution (LTE), LTE-Advanced(LTE-A), GSM (registered trademark), UMTS, W-CDMA, CDMA 2000, WiMAX,WiMAX 2 or IEEE 802.16.

Here, one device may function as the transmitting station 100 or thereceiving station 200. In addition, one device may function as both thetransmitting station 100 and the receiving station 200. For example, aUE may serve as the receiving station 200 that receives data from an eNBthrough downlink and also serve as the transmitting station 100 thattransmits data to the eNB through uplink. 1G In addition, an eNB mayserve as the receiving station 200 that receives data from a UE throughuplink and also serve as the transmitting station 100 that transmitsdata to the UE through downlink

Furthermore, UEs may perform wireless communication with each other. Inthe example illustrated in FIG. 5, a UE 100B directly performs wirelesscommunication with a UE 200C. Such a communication system is also calleddevice-to-device (D2D) communication. D2D communication may berecognized as communication other than communication between an eNB anda UE in a cellular system. In addition, communication in a wirelesscommunication system having no centralized control node which is aspowerful as an eNB in a cellular system may be included in D2Dcommunication in a broad sense. For example, a wireless local areanetwork (WLAN) system may be an example of such a wireless communicationsystem.

The communication control device 300 is a device that cooperativelycontrols wireless communication in the wireless communication system 1.In the example illustrated in FIG. 5, the communication control device300 is a server. For example, the communication control device 300controls wireless communication in the transmitting station 100 and thereceiving station 200. In addition to the example illustrated in FIG. 5,the communication control device may be realized, for example, as anydevice (physical device or logical device) inside or outside of thetransmitting station 100, the receiving station 200 or the core network500.

Operations related to wireless communication in the wirelesscommunication system 1 according to the present embodiment will bedescribed.

(1-2-2. Downlink Case)

First, a process when wireless communication is performed from an eNB toa UE will be described.

In a normal cellular system, an eNB manages/controls radio resources ina centralized manner in downlink and uplink wireless communication inmany cases. In the case of downlink, first of all, the eNB announces, toa UE, radio resources to which a downlink data channel (e.g., PDSCH) tobe received has been allocated. For such announcement, a control channel(e.g., PDCCH) is generally used. Then, the eNB transmits data to each UEusing downlink radio resources allocated to each UE.

The UE attempts to receive and decode a transmitted signal using theradio resource of the downlink data channel announced by the eNB. The UEtransmits an ACK signal to the eNB when the UE has successfully decodedthe signal and transmits a NACK signal to the eNB when the UE has failedto decode the signal Success or failure of decoding may be determined bya result of a cyclic redundancy check (CRC) check added to thetransmitted data, or the like, for example.

The eNB determines that data transmission has failed when the NACKsignal is received from the UE or no return signal is received. Then,the eNB performs a retransmission process for retransmitting the data ofwhich transmission has failed. In the retransmission process,announcement of radio resources to which a downlink data channel hasbeen allocated from the eNB to the UE and data transmission using theannounced radio resources are performed as in the process describedabove. The eNB repeats the retransmission process until an ACK signal isreceived from the UE or a predetermined maximum number ofretransmissions is reached.

(1-2-3. Uplink Case)

Next, a process when wireless communication is performed from a UE to aneNB will be described.

Differently from the downlink, an eNB performs announcement of radioresources and a UE performs data transmission in the uplink case,whereas an eNB performs both announcement of radio resources andtransmission of data in the downlink case. Specifically, the eNBannounces, to the UE, radio resources to which an uplink data channel(e.g., PUSCH) to be used for transmission has been allocated. A controlchannel (e.g., PDCCH) is generally used for the announcement. Then, theUE transmits data to the eNB using the announced uplink data channel.

The retransmission process is similar to the downlink case. For example,the UE determines that data transmission has failed and performsretransmission when a NACK signal is received from the eNB or no returnsignal is received. Here, the eNB may perform announcement of radioresources to be used for the UE for retransmission simultaneously withtransmission of the NACK signal because the eNB controls and managesradio resources of uplink data channels.

(1-2-4. D2D Communication Case)

Lastly, a process in D2D communication in which wireless communicationis performed between UEs will be described.

A UE at a transmitting side may transmit data without announcing radioresources used for transmission. The UE at the transmitting side mayrecognize radio resources to be used for transmission, for example,through announcement from an external device or by performing carriersensing, spectrum sensing or the like. The retransmission process is thesame as the downlink case and the uplink case described above.

2. EXAMPLES OF CONFIGURATIONS

Examples of basic configurations of the transmitting station 100, thereceiving station 20 and the communication control device 300 accordingto the present embodiment will be described with reference to FIGS. 6 to8.

[2-1. Example of Configuration of Transmitting Station]

FIG. 6 is a block diagram illustrating an example of a logicalconfiguration of the transmitting station 100 according to the presentembodiment. As illustrated in FIG. 6, the transmitting station 100includes a wireless communication unit 110, a storage unit 120 and acontroller 130.

(1) Wireless Communication Unit 110

The wireless communication unit 110 performs transmission-reception ofdata to/from other wireless communication devices. The wirelesscommunication unit 110 according to the present embodiment has afunction of performing wireless communication with other wirelesscommunication devices using IDMA. For example, the wirelesscommunication unit 110 interleaves transmission target data usinginterleave setting allocated to the transmitting station 100 andtransmits the interleaved transmission target data to the receivingstation 200. The wireless communication unit 110 may performtransmission/reception of control information to/from the receivingstation 100 or the communication control device 300. The detailedfunctional configuration of the wireless communication unit 110 will bedescribed below.

(2) Storage Unit 120

The storage unit 120 has a function of storing various types ofinformation. For example, the storage unit 120 stores informationannounced by the communication control device 300.

(3) Controller 130

The controller 130 serves as an operation processing device and acontrol device and controls the overall operation in the transmittingstation 100 according to various programs. For example, the controller130 has a function of controlling interleave setting in an interleaveprocess for IDMA through the wireless communication unit 110.Specifically, the controller 130 controls at least one of an interleavepattern and an interleave length used by an interleaver. The controller130 may facilitate signal separation at the receiving station 200 byvarying at least the interleave length. The detailed functionalconfiguration of the controller 130 will be described below.Hereinafter, the interleave process for IDMA is simply called aninterleave process or interleave.

[2-2. Example of Configuration of Receiving Station]

FIG. 7 is a block diagram illustrating an example of a logicalconfiguration of the receiving station 200 according to the presentembodiment. As illustrated in FIG. 7, the receiving station 200 includesa wireless communication unit 210, a storage unit 220 and a controller230.

(1) Wireless Communication Unit 210

The wireless communication unit 210 performs transmission/reception ofdata to/from other wireless communication devices. The wirelesscommunication unit 210 according to the present embodiment has afunction of performing wireless communication with other wirelesscommunication devices using IDMA. For example, the wirelesscommunication unit 210 performs a deinterleave process corresponding tointerleave setting allocated to the transmitting station 100 that is atransmission source on a wireless signal received from the transmittingstation 100 to obtain data. The wireless communication unit 210 mayperform transmission/reception of control information to/from thetransmitting station 100 or the communication control device 300. Thedetailed functional configuration of the wireless communication unit 210will be described below.

(2) Storage Unit 220

The storage unit 220 has a function of storing various types ofinformation. For example, the storage unit 220 stores informationannounced by the communication control device 300.

(3) Controller 230

The controller 230 serves as an operation processing device and acontrol device and controls the overall operation in the receivingstation 200 according to various programs. For example, the controller230 has a function of controlling the wireless communication unit 210 toperform a deinterleave process depending on interleave setting used foran interleave process for IDMA by another wireless communication device.Specifically, the controller 230 controls deinterleave setting inresponse to at least one of an interleave pattern and an interleavelength used for the interleave process by the transmitting station 100that is a wireless signal transmission source. Further, deinterleavesetting is setting related to at least one of a deinterleave length anda deinterleave pattern, for example. The detailed functionalconfiguration of the controller 230 will be described below.

[2-3. Example of Configuration of Communication Control Device]

FIG. 8 is a block diagram illustrating an example of a logicalconfiguration of the communication control device 300 according to thepresent embodiment. As illustrated in FIG. 8, the communication controldevice 300 includes a communication unit 310, a storage unit 320 and acontroller 330.

(1) Communication Unit 310

The communication unit 310 is a communication interface for relayingcommunication of the communication control device 300 with otherdevices. The communication unit 310 performs transmission/reception ofdata to/from other devices in a wireless or wired manner. For example,the communication unit 310 performs communication with the transmittingstation 100 or the receiving station 200 directly or indirectly throughany communication node.

Meanwhile, the communication control device 300 may be the same as orindependent from the transmitting station 100 or the receiving station200. Here, the sameness/independence includes sameness/independence in alogical sense in addition to sameness/independence in a physical sense.The communication unit 310 performs transmission and reception through awired or wireless communication circuit for an independent device andperforms transmission and reception inside of the device for the samedevice.

(2) Storage Unit 320

The storage unit 320 has a function of storing various types ofinformation. For example, the storage unit 320 stores interleave settingallocated to each transmitting station 100.

(3) Controller 330

The controller 330 serves as an operation processing device and acontrol device and controls the overall operation in the communicationcontrol device 300 according to various programs. For example, thecontroller 330 allocates interleave setting to each transmitting station100 such that interleave settings do not overlap between transmittingstations.

The examples of the basic configurations of the transmitting station100, the receiving station 200 and the communication control device 300according to the present embodiment have been described. Next, anexample of an operation process of the wireless communication system 1according to the present embodiment will be described with reference toFIG. 9.

3. EXAMPLE OF OPERATION PROCESS

FIG. 9 is a sequence diagram illustrating an example of the flow of awireless communication process executed in the wireless communicationsystem 1 according to the present embodiment. As illustrated in FIG. 9,the transmitting station 100 and the receiving station 200 are involvedin the present sequence. In the present sequence, the transmittingstation 100 is considered to function as the communication controldevice 300.

As illustrated in FIG. 9, first of all, the transmitting station 100decides interleave setting in step S102. For example, the controller 130decides an interleave length and an interleave pattern. The process inthis step will be described in detail below.

Then, the transmitting station 100 transmits control information to thereceiving station 200 in step S104. The control information may includeinformation about the interleave setting. The content of the controlinformation will be described in detail below.

Subsequently, the receiving station 200 decides deinterleave setting instep S106. For example, the controller 230 decides a deinterleave lengthand a deinterleave pattern corresponding to the interleave setting usedin the transmitting station 100. The process in this step will bedescribed in detail below. Incidentally, this process may be performedbefore the control information is transmitted (before step S104) orafter a wireless signal corresponding to a decoding target istransmitted from the transmitting station 100 (after step S110).

Then, the transmitting station 100 performs an interleave process instep S108. The controller 130 controls the wireless communication unit110 to perform the interleave process depending on the interleavesetting decided in step S102.

Thereafter, the transmitting station 100 transmits the wireless signalin step S110.

In step S112, the receiving station 200 performs a deinterleave processon the received wireless signal. The controller 230 controls thewireless communication unit 210 to perform the deinterleave processdepending on the deinterleave setting decided in step S106.

In step S114, the receiving station 200 acquires data transmitted fromthe transmitting station 100.

4. DETAILS OF FUNCTIONS [4-1. Processing of Physical Layer inTransmitting Station]

FIG. 10 is a block diagram illustrating an example of a logicalconfiguration of the wireless communication unit 110 of the transmittingstation 100 according to the present embodiment. FIG. 10 illustrates anexample of a configuration of the part of the wireless communicationunit 110 in which an interleave process for a transport block (TB) of abit sequence corresponding to a transmission target is performed by thetransmitting station 100. Although FIG. 10 shows a configuration examplein which a turbo code is considered as an example of forward errorcorrection (FEC), other FEC codes such as a convolutional code and alow-density parity-check (LDPC) code may be used in addition to theturbo code. As illustrated in FIG. 10, the wireless communication unit110 includes a CRC adding unit 111, a CB segmentation unit 112, a CRCadding unit 113, an FEC coding unit 114, a rate-matching unit 115, a CBconnecting unit 116, an interleaver setting unit 117 and a CWinterleaver 118.

First, the CRC adding unit 111 adds a CRC to the TB. Then, the CBsegmentation unit 112 segments the sequence to which CRC bits have beenadded into one or more error correction code sequence code blocks (CBs)depending on a code length of the turbo code. Processing of thesegmented CBs may be performed through as many parallel processes as thenumber (C) of CBs. As processes for each CB, the CRC adding unit 113adds a CRC to each CB, the FEC coding unit 114 performs FEC coding(e.g., turbo coding), and the rate-matching unit 115 performs ratematching to adjust a coding rate. Thereafter, the CB connecting unit 116connects CBs output from the rate-matching unit 115 to generate a singlebit sequence. The bit sequence is handled as a codeword (CW). The CWcorresponds to the TB after coding. The interleaver setting unit 117performs interleave setting of the CW interleaver 118 depending on aninput parameter. Further, the controller 130 inputs, as a parameter,information acquired from control information announced by an eNB or thelike, for example, using a control channel to the interleaver settingunit 117. Then, the CW interleaver 118 executes an interleave processfor the CW generated by connecting the CBs.

Next, bit sequence lengths in the above process will be described. Thesequence length of the bit sequence of the original TB is considered tobe A. The sequence after CRC bit addition by the CRC adding unit 111 isB (>=A). In addition, the sequence length of an r-th CB is Kr inresponse to the code length of the turbo code. The sequence length ofthe CW generated by the CB connecting unit 116 is G′. The sequencelength of the CW output from the CW interleaver 118 is G. G′ and G maybe identical. Furthermore. G′ may differ from G because padding may beperformed before and after the CW interleaver 118.

[4-2. Interleave Setting] [4-2-1. Interleave Length]

The interleave length controlled by the controller 130 of thetransmitting station 100 according to the present embodiment is thesequence length of the CW in FIG. 10, for example. The interleave lengthmay be a sequence length of the sum of sequences output from a pluralityof interleavers when the plurality of interleavers are used, instead ofthe length of a sequence output from a single interleaver (the CWinterleaver 118 in the example shown in FIG. 10).

In a general IDMA system, the interleave length G may be determined onthe basis of a transmitted bit sequence (TB in the example shown in FIG.10) and an FEC coding rate. When application of IDMA to a cellularsystem is considered, it is desirable to determine the interleave lengthG on the basis of the quantity of radio resources allocated to a user(e.g., the number of subcarriers, the number of resource blocks, thenumber of spatial layers and the like) and a modulation scheme (e.g.,QPSK, 16-QAM, 64-QAM, 256-QAM or the like).

Accordingly, the controller 130 of the transmitting station 100according to the present embodiment controls the interleave length onthe basis of the quantity of radio resources available for transmissionby the wireless communication unit 110 and a modulation scheme usedtherefor. For example, the controller 130 determines the interleavelength G such that the interleave length G satisfies the followingformula.

[Math. 1]

G≤N _(RE) Q _(m)  Formula 1

Here, N_(RE) is the number of resource elements available for actualdata transmission from among radio resources allocated to the user. Inaddition, Q_(m) is a bit multiplex number per resource element (whichusually depend on a modulation scheme). Meanwhile, when the transmittingstation 100 employs transmission diversity, the controller 130 mayadjust the number NR of resource elements in response to thetransmission diversity. For example, when the transmitting station 100employs N_(TD)-order transmission diversity, the number N_(RE) ofresource elements available for actual data transmission may becontrolled to be 1/N_(TD) for the number of physical resource elements.

The controller 130 may determine the value G such that the equality signof Math. 1 is achieved in order to maximize resource utilizationefficiency of the entire system.

When the wireless communication system 1 uses a multiplexing technologysuch as a spreading technology or a spatial multiplexing technology inaddition to IDMA, the controller 130 may determine the interleave lengthG further based on a spreading factor. For example, the controller 130determines the interleave length G such that the interleave length Gsatisfies the following formula.

$\begin{matrix}\left\lbrack {{Math}.\mspace{14mu} 2} \right\rbrack & \; \\{G \leq \frac{N_{M}N_{RE}Q_{m}}{S\; F}} & {{Formula}\mspace{14mu} 2}\end{matrix}$

Here, SF is a spreading factor. In addition, N_(M) is a multiplexnumber. The controller 130 may reflect the influence with respect to thespreading factor and spatial multiplexing in a method of countingN_(RE).

(Padding Process)

The controller 130 may control the wireless communication unit 110 toperform padding when the length of an input sequence for an interleaveprocess does not reach the interleave length. For example, if thesequence length G′ input to the CW interleaver 118 in FIG. 10 does notreach the interleave length G, the controller 130 controls the wirelesscommunication unit 110 to perform padding before or after the interleaveprocess by the CW interleaver 118.

For example, the controller 130 may control the wireless communicationunit 110 to perform padding on the input sequence for the interleaveprocess. For example, the CW interleaver 118 adds padding bitscorresponding to N_(p)=G−G′ bits to the input bit sequence input theretobefore the interleave process is executed when G′<G.

For example, the input bit sequence input to the interleaver is

[Math. 3]

b′ _(k′) ,k′=0, . . . ,G′−1  Formula 3

a target bit sequence corresponding to an object of the interleaveprocess is

[Math. 4]

b _(k) ,k=0, . . . ,G−1  Formula 4

and a padding bit sequence is

[Math. 5]

p _(k″) ,k″=0, . . . ,N _(p)−1  Formula 5

The padding bit sequence may be all {0}, all {1}, any random number of{0, 1} or a predetermined sequence of {0, 1}. The padding process by theCW interleaver 188 in this case will be described with reference to FIG.1.

FIG. 11 is a flowchart illustrating an example of the flow of thepadding process executed in the transmitting station 100 according tothe present embodiment. As illustrated in FIG. 11, first of all, the CWinterleaver 118 determines whether G′=G in step S202.

When it is determined that G′=G (S202/YES), the CW interleaver 118 usesthe input bit sequence as a target bit sequence as it is according tothe following formula in step S204.

[Math. 6]

b _(k) =b′ _(k) ,k=0, . . . ,G−1  Formula 6

On the other hand, when it is determined that G′<G (S202/NO), the CWinterleaver 118 uses a sequence obtained by adding the padding bitsequence to the input bit sequence as a target bit sequence according tothe following formula.

[Math. 7]

b _(k) =p _(k) ,k=0, . . . ,N _(p)−1,

b _(N) _(p) _(k′) =b′ _(k′) ,k′=0, . . . ,G′−1  Formula 7

Accordingly, the sequence length of the target bit sequence becomes theinterleave length G and the sequence length of an output bit sequenceoutput from the CW interleaver 118 becomes G.

Then, the CW interleaver 118 performs an interleave process in stepS208.

In addition, the controller 130 may control the wireless communicationunit 110 to perform padding on the output sequence of the interleaveprocess. For example, when G′<G, the CW interleaver 118 adds paddingbits corresponding to N_(p)=G−G′ bits to the output bit sequence afterexecution of the interleave process. The padding process by the CWinterleaver 118 in this case will be described with reference to FIG.12.

FIG. 12 is a flowchart illustrating an example of the flow of thepadding process executed in the transmitting station 100 according tothe present embodiment. As illustrated in FIG. 12, first of all, the CWinterleaver 118 performs an interleave process in step S302.

Then, the CW interleaver 118 determines whether G′=G in step S304.

When it is determined that G′=G (S304/YES), the CW interleaver 118outputs an output bit sequence as it is in step S306.

On the other hand, when it is determined that G′<G (S304/NO), the CWinterleaver 118 outputs a sequence obtained by adding a padding bitsequence to the output bit sequence in step S308. Accordingly, thesequence length of the output bit sequence becomes the interleave lengthG.

An example of the padding process has been described.

For example, the rate-matching unit 115 may adjust the sequence lengthof the output bit sequence as another method for making G′=G or G′≤G.

(Interleave Length Decision Process)

For example, the controller 130 decides the interleave length G usingthe number N_(RE) of resource elements available for actual datatransmission and the bit multiplex number Q_(m) (bit number) perresource element. The procedure of this decision process may be changeddepending on the type of the transmitting station 100. An example of theinterleave length decision process depending on the type of thetransmitting station 100 will be described below.

(A) Transmitting Station to which Radio Resources Used for Transmissionare Allocated by Other Devices

For example, the transmitting station 100 is a UE in a cellular system.A method of deciding the interleave length G will be described withreference to FIG. 13.

FIG. 13 is a flowchart illustrating an example of the flow of aninterleave length decision process executed in the transmitting station100 according to the present embodiment.

First, the wireless communication unit 110 receives and decodes controlinformation in step S402. For example, the wireless communication unit110 receives and decodes control information transmitted from an eNBusing a control channel. For example, the control information mayinclude information about radio resources and a modulation schemeavailable for transmission of the transmitting station 100.

Subsequently, the controller 130 acquires information about radioresources allocated for transmission by the transmitting station 100 instep S404. For example, the information about the radio resources isinformation indicating the number of resource blocks allocated asresources in the frequency direction or information indicating whichresource blocks have been allocated.

Thereafter, the controller 130 acquires the number N_(RE) of resourceelements available for actual data transmission in step S406. Forexample, the controller 130 acquires the number obtained by subtractingthe number of resource elements that cannot be used for datatransmission, such as a reference signal, a synchronization signal and acontrol signal, from the radio resources allocated to the transmittingstation 100. Further, when the number of resources allocated in thefrequency direction is previously determined such as a case in which theentire band is allocated to the transmitting station 100, for example,the processes in steps S404 and S406 may be omitted.

Next, the controller 130 acquires, from the control information receivedin step S402, information indicating a modulation scheme to be used fortransmission by the transmitting station 100 in step S408. For example,the information indicating the modulation scheme may be informationdirectly indicating the modulation scheme, such as a channel qualityindicator (CQI) in LTE. In addition, the information indicating themodulation scheme may be information indirectly indicating themodulation scheme, such as a modulation and coding set (MCS) in LTE, forexample. It is desirable that the information indicating the modulationscheme be specified in the wireless communication system 1 in advance.

Then, the controller 130 acquires a bit number Q_(m) per resourceelement, allocated for transmission by the controller 130 in step S410.For example, the controller 130 acquires the bit number Q_(m) perresource element from the modulation scheme indicated by the informationacquired in step S408. When the control information includes informationindicating the bit number Q_(m) per resource element, the controller 130may acquire the bit number Q_(m) per resource element from the controlinformation.

In addition, the controller 130 decides the interleave length G in stepS412. For example, the controller 130 decides the interleave length G asG=N_(RE)×Q_(m).

(B) Transmitting Station Allocating (or Deciding) Radio Resources Usedfor Transmission by Itself.

For example, the transmitting station 100 is an eNB in a cellularsystem. In addition, the transmitting station 100 may be a device of thewireless communication system 1, to which no radio resources areallocated, for example. A method of deciding the interleave length Gwill be described with reference to FIG. 14.

FIG. 14 is a flowchart illustrating an example of the flow of theinterleave length decision process executed in the transmitting station100 according to the present embodiment. A processing example whentransmission to a user i is performed on the assumption of one-to-onetransmission is described in this flow. In the case of one-to-multipletransmission, there are a plurality of user indices i.

As illustrated in FIG. 14, first of all, the controller 130 acquiresinformation about radio resources used by the transmitting station 100for transmission to the user i in step S502. For example, theinformation about the radio resources is information indicating thenumber of resource blocks used as resources in the frequency directionor information indicating which resource blocks are used.

Then, the controller 130 acquires the number N_(RE) of resource elementsavailable for actual data transmission to the user i in step S504. Forexample, the controller 130 acquires the number obtained by subtractingthe number of resource elements that cannot be used for datatransmission, such as a reference signal, a synchronization signal and acontrol signal, from the radio resources used by the transmittingstation 100. When the number of resources allocated in the frequencydirection is previously determined, the processes in steps S502 and S504may be omitted.

Subsequently, the controller 130 acquires information indicating amodulation scheme to be used for transmission to the user i in stepS506. For example, the controller 130 acquires the informationindicating the modulation scheme with reference to information stored inthe storage unit 120.

Next, the controller 130 acquires a bit number Q_(m) per resourceelement used for transmission to the user i in step S508. For example,the controller 130 acquires the bit number Q_(m) per resource elementfrom the modulation scheme indicated by the information acquired in stepS408. The controller 130 may directly acquire information indicating thebit number Q_(m) per resource element.

Then, the controller 130 decides the interleave length G in step SS 10.For example, the controller 130 decides the interleave length G asG=N_(RE)×Q_(m).

An example of the flow of the interleave length decision process hasbeen described.

As described above, it is desirable to previously specify theinformation indicating a modulation scheme, such as a CQI or MCS, in thewireless communication system 1. An example of specification of the MCSis shown in table 1 below.

TABLE 1 MCS Index Modulation Order TBS Index Redundancy Version I_(MCS)Q_(m) I_(TBS) rv_(idx) 0 2 0 0 1 2 1 0 2 2 2 0 3 2 3 0 4 2 4 0 5 2 5 0 62 6 0 7 2 7 0 8 2 8 0 9 2 9 0 10 2 10 0 11 4 10 0 12 4 11 0 13 4 12 0 144 13 0 15 4 14 0 16 4 15 0 17 4 16 0 18 4 17 0 19 4 18 0 20 4 19 0 21 619 0 22 6 20 0 23 6 21 0 24 6 22 0 25 6 23 0 26 6 24 0 27 6 25 0 28 6 260 29 reserved 1 30 2 31 3

In the above table 1, the first column indicates an MCS index and thesecond column corresponds to a bit number Q_(m) per resource element.

In addition, an example of specification of the CQI is shown in table 2below.

TABLE 2 COI Modulation Order code rate × index modulation Q_(m) 1024efficiency 0 out of range 1 QPSK 2 78 0.1523 2 QPSK 2 120 0.2344 3 QPSK2 193 0.3770 4 QPSK 2 308 0.6016 5 QPSK 2 449 0.8770 6 QPSK 2 602 1.17587 16QAM 4 378 1.4766 8 16QAM 4 490 1.9141 9 16QAM 4 616 2.4063 10 64QAM6 466 2.7305 11 64QAM 6 567 3.3223 12 64QAM 6 666 3.9023 13 64QAM 6 7724.5234 14 64QAM 6 873 5.1152 15 64QAM 6 948 5.5547

In the above table 2, the first column indicates a CQI index, the secondcolumn indicates a modulation scheme and the third column corresponds toa bit number Q_(m) per resource element.

[4-2-2. Interleave Pattern]

The controller 130 of the transmitting station 100 according to thepresent embodiment may control an interleave pattern in an interleaveprocess by the wireless communication unit 110. In IDMA, it is possibleto enable transmission signal multiplexing and signal separation in areceiving station by making interleave patterns different fortransmitting stations. Accordingly, the controller 130 of thetransmitting station 100 according to the present embodiment, forexample, controls an interleave pattern depending on the number ofretransmissions. For example, the controller 130 decides the interleavepattern by the following formula.

$\begin{matrix}{\mspace{79mu} \left\lbrack {{Math}.\mspace{14mu} 8} \right\rbrack} & \; \\{{n\left( {m,I_{User},I_{Cell},S_{Tbs},P_{Harq},N_{Retx},{SFN},O_{Int},G} \right)} = {\left( {\frac{\left( {{2I_{User}} + 1} \right){m\left( {m + 1} \right)}}{2} + I_{Cell} + S_{Tbs} + P_{Harq} + N_{Retx} + {SFN} + O_{Int}} \right)\; {mod}\; G}} & {{Formula}\mspace{14mu} 8}\end{matrix}$

Here, I_(User) is a user identifier, for example, a user ID or a radionetwork temporary identifier (RNTI). G is an interleave length. I_(Cell)is a cell ID such as a cell-RNTI. S_(Tbs) is a bit number of acorresponding TB (transport block size). Furthermore. S_(Tbs) may beI_(TBS) in the specification of MCS. P_(Harq) is a process ID of ahybrid automatic repeat request (HARQ). N_(Retx) is the number ofretransmissions of the corresponding TB, for example, 0 in the case ofinitial transmission and 1 in the case of the first retransmission. SFNis a system frame number of radio resources used for retransmission.O_(Int) is an offset value considered in the interleave pattern. Forexample, this value may be designated by an eNB device or other devicesin the wireless communication system 1. It is desirable that O_(Int)<G.This is because the offset value is canceled by a modulo operation whenset to a value equal to or greater than G.

The above formula 8 represents that an m-th bit of the input bitsequence of the CW interleaver 118 becomes an n-th bit of the output bitsequence, as illustrated in FIG. 15. FIG. 15 illustrates an interleavepattern control method according to the present embodiment. According tothe formula, an interleave pattern is qualitatively specified even in asystem having a dynamically variable interleave length G. Since theinterleave pattern is specified according to the formula, thetransmitting station 100 may not store all interleave patterns relatedto a variable interleave length G and can reduce storage load in thestorage unit 120.

Furthermore, the controller 130 may vary the interleave pattern for eachretransmission depending on the number N_(Retx) of retransmissions orthe system frame number SFN, as represented by the above formula 8. Thecontroller 130 may obtain a diversity effect and reduce interference byvarying the interleave pattern for each retransmission to randomize theinterleave pattern.

The controller 130 may decide the interleave pattern through differentmethods depending on transmission directions such as uplink, downlinkand D2D communication. For example, the controller 130 may decide theinterleave pattern using different formulas depending on transmissiondirections. In addition, the controller 130 may decide the interleavepattern using a formula, obtained by adding a parameter La indicating atransmission direction to the formula 8, as represented by the followingformula.

$\begin{matrix}{\mspace{79mu} \left\lbrack {{Math}.\mspace{14mu} 9} \right\rbrack} & \; \\{{n\left( {m,I_{User},I_{Cell},S_{Tbs},P_{Harq},N_{Retx},L_{d},{SFN},O_{Int},G} \right)} = {\left( {\frac{\left( {{2I_{User}} + 1} \right){m\left( {m + 1} \right)}}{2} + I_{Cell} + S_{Tbs} + P_{Harq} + N_{Retx} + L_{d} + {SFN} + O_{Int}} \right)\; {mod}\; G}} & {{Formula}\mspace{14mu} 9}\end{matrix}$

Ld is a parameter having a value depending on a relevant transmissiondirection. For example, the parameter may have a value such as 0 in thecase of downlink, 10 in the case of uplink or 100 in the case of D2Dcommunication.

The CW interleaver 118 may be configured as a single interleaver orinclude a plurality of interleavers. Hereinafter, a plurality ofinterleavers included in the CW interleaver 118 are calledsub-interleavers. The controller 130 may control the interleave patternby switching sub-interleavers performing interleave processes.Hereinafter, examples in which the CW interleaver 118 includes aplurality of sub-interleavers formed in multiple stages will bedescribed with reference to FIGS. 16 to 18.

FIG. 16 is a block diagram illustrating an internal configuration of theCW interleaver 118 according to the present embodiment. In the exampleillustrated in FIG. 16, the CW interleaver 118 includes a first-stagesub-interleaver 1181, a second-stage sub-interleaver 1182, a third-stagesub-interleaver 1183, a fourth-stage sub-interleaver 1184 and a PHYlayer controller 1185. The first-stage sub-interleaver 1181 is a commoninterleaver. The second-stage sub-interleaver 1182 is an interleaverhaving a pattern that is variable according to user ID and/or cell ID.The third-stage sub-interleaver 1183 is an interleaver having a patternthat is variable according to SFN. The fourth-stage sub-interleaver 1184is an interleaver having a pattern that is variable according to thenumber of transmissions and/or the number of retransmissions. The PHYlayer controller 1185 inputs corresponding parameters to thesub-interleavers included in the CW interleaver 118 on the basis ofcontrol information acquired from a control channel, for example. Forexample, the PHY layer controller 1185 inputs the user ID and/or thecell ID to the second-stage sub-interleaver 1182. In addition, the PHYlayer controller 1185 inputs the SFN to the third-stage sub-interleaver1183. Furthermore, the PHY layer controller 1185 inputs the number oftransmissions and/or the number of retransmissions to the fourth-stagesub-interleaver 1184.

As illustrated in the example of FIG. 16, it is desirable that thesub-interleavers included in the CW interleaver 118 perform differentinterleave processes using different parameters as inputs. Accordingly,the controller 130 may control use/non-use of each sub-interleaver moreeasily according to a situation. Meanwhile, the order of thesub-interleavers is optional and the number of sub-interleavers andinput parameters are also optional. In addition, the sub-interleaversmay have any interleave lengths and have the same interleave length ordifferent interleave lengths. For example, the interleave lengths may beinitially set to G′ and changed to G in the middle of the process when apadding process is performed. Further, it is desirable that thesub-interleavers have the same interleave length.

FIG. 17 is a block diagram illustrating an internal configuration of theCW interleaver 118 according to the present embodiment. The CWinterleaver 118 illustrated in FIG. 17 may switch between execution ofan interleave process of each sub-interleaver process and non-executionof the interleave process by passing an input parameter depending oninput parameters.

FIG. 18 is a block diagram illustrating an internal configuration of theCW interleaver 118 according to the present embodiment. The CWinterleaver 118 illustrated in FIG. 18 has a combination of a pluralityof sub-interleavers in each stage. For example, the CW interleaver 118has a combination of first-stage sub-interleavers 1181A and 1181B in thefirst stage. In addition, the CW interleaver 118 has a combination ofsecond-stage sub-interleavers 1182A and 1182B in the second stage.Furthermore, the CW interleaver 118 has a combination of third-stagesub-interleavers 1183A and 1183B in the third stage. The CW interleaver118 has a combination of fourth-stage sub-interleavers 1184A and 1184Bin the fourth stage. The CW interleaver 118 may switch interleaveprocesses using any sub-interleavers of the combinations ofsub-interleavers in the respective stages.

When the CW interleaver 118 is formed in multiple stages, various inputparameters are considered for each sub-interleaver. The following table3 shows an example of parameters. Here, it is desirable that parametershaving different update intervals be input to respectivesub-interleavers. In this case, the CW interleaver 118 may appropriatelychange interleave patterns with time. Furthermore, the CW interleaver118 may change a configuration of sub-interleavers with littleadditional information.

TABLE 3 Parameter Detailed example of change period parameters Specificexamples Invariable Common carrier ID PLMN (Public Land Mobile Network),PSTN (Permanent or Node category type (Public Switched TelephoneNetwork), MCC Semipermanent) Link direction (Mobile Country Code), MNC(Mobile Network Code) Category 1-10, MAC address Downlink, Uplink Longperiod User ID RNTI (Radio Network Temporary Identifier) IP addressIPv4, IPv6 Middle period Frame number SFN (System Frame Number) Shortperiod Subframe ID Subframe ID Irregular Cell ID RNTI, SSID (Service SetIdentifier), BSS HARQ Info (Basic Service Set) CSI (Channel State NewData Indicator Information) Info Channel Quality Indicator, PrecodingMatrix MCS (Modulation and Indicator, Rank Indicator, Precoding TypeCoding Set) Info Indicator Retransmission/initial MCS index, TBS indextransmission

[4-3. Interleave Setting Related to Retransmission]

The controller 130 of the transmitting station 100 may controlinterleave setting depending on a retransmission process type. Thecontroller 130 may control an interleave length or an interleave patterndepending on a retransmission process type. Hereinafter, interleavesetting related to HARQ will be described first.

[4-3-1. Adaptive/Non-Adaptive]

First, two types of HARQ, adaptive HARQ and non-adaptive HARQ, areconsidered as an example of retransmission type. Adaptive HARQ is HARQhaving a modulation scheme that is variable for each retransmission.When the transmitting station 100 employs adaptive HARQ, thetransmitting station 100 can increase a degree of freedom of resourcecontrol. However, the transmitting station 100 performs signaling fordesignating a modulation scheme during retransmission. On the otherhand, non-adaptive HARQ is HARQ having a fixed modulation scheme duringretransmission. When the transmitting station 100 employs non-adaptiveHARQ, the transmitting station 100 can omit signaling for designating amodulation scheme even if a degree of freedom of resource controldecreases.

Incidentally, when the transmitting station 100 employs HARQ, it isdesirable that a TB size (bit number per TB) be identical to the TB sizeduring previous transmission of the TB that is a retransmission targetbecause signal combining in the receiving station 200 becomes simple.

Hereinafter, an example of an interleave length decision processdepending on an HARQ type will be described with reference to FIG. 19.

FIG. 19 is a flowchart illustrating an example of the flow of aninterleave length decision process executed in the transmitting station100 according to the present embodiment.

As illustrated in FIG. 19, first of all, the controller 130 determineswhether a TB of a transmission target is an initially transmitted TB instep S602.

When the TB is determined to be the initially transmitted TB (S602/YES),the controller 130 decides an interleave length through a procedure forinitial transmission in step S604. Here, the procedure for initialtransmission refers to the processes described as examples in FIGS. 13and 14.

When the TB is determined to be a retransmitted TB (S602/NO), thecontroller 130 determines whether adaptive HARQ is employed in stepS606. Criteria for the determination will be described below.

When it is determined that adaptive HARQ is employed (S606/YES), theprocess proceeds to step S604 and the controller 130 decides theinterleave length through the procedure for initial transmission. Thisis because a modulation scheme or the number of resource elements may bechanged in the case of adaptive HARQ.

On the other hand, when it is determined that non-adaptive HARQ isemployed (S606/NO), the controller 130 determines whether the numberN_(RE) of available resource elements differs from that during theprevious transmission in step S608. The determination is performedbecause the number of available resource elements may change even if thesame number of resource blocks is available.

When it is determined that the number of available resource elementsdiffers from that during the previous transmission (S608/YES), theprocess proceeds to step S604 and the controller 130 decides theinterleave length through the procedure for initial transmission.

On the other hand, when it is determined that the number of availableresource elements is identical to that during the previous transmission(S608/NO), the controller 130 employs the same interleave length as thatduring the previous transmission again in step S610.

Hereinafter, criteria for determining whether adaptive HARQ is employedin step S606 will be described with reference to FIG. 20. Here, thetransmitting station 100 is regarded as a transmitting station to whichradio resources used for transmission are allocated by other devices,such as a UE in a cellular system. When the transmitting station 100 isa transmitting station that allocates (or decides) radio resources usedfor transmission by itself, such as an eNB in a cellular system, whetheradaptive HARQ is employed may be determined based on any determinationcriteria.

FIG. 20 is a flowchart illustrating an example of the flow of a HARQtype determination process executed in the transmitting station 100according to the present embodiment.

As illustrated in FIG. 20, first of all, the controller 130 acquires anMCS from control information announced by an eNB or the like using acontrol channel, for example, in step S702. Here, the wirelesscommunication system 1 may employ the specification of MCS shown in theabove table 1.

Subsequently, the controller 130 determines whether a corresponding TBSis “reserve” in the specification of MCS shown in the table 1. Thecontroller 130 may determine whether the corresponding TBS is a specificvalue instead of determining whether the corresponding TBS is “reserve.”

When the corresponding TBS is not “reserve” (S704/NO), the controller130 determines that adaptive HARQ is employed in step S710.

On the other hand, when the corresponding TBS is “reserve” (S704/YES),the controller 130 determines whether a corresponding modulation orderis “reserve” in the specification of MCS shown in the table 1 in stepS706. The controller 130 may determine whether the correspondingmodulation order is a specific value instead of determining whether thecorresponding modulation order is “reserve.”

When the corresponding modulation order is not “reserve” (S706/NO), thecontroller 130 determines that adaptive HARQ is employed in step S710.

On the other hand, when the corresponding modulation order is “reserve”(S706/YES), the controller 130 determines that non-adaptive HARQ isemployed in step S708.

In addition, when a flag indicating which one of adaptive HARQ andnon-adaptive HARQ is to be employed is announced, the transmittingstation 100 may determine which HARQ is employed on the basis of theannouncement.

Adaptive HARQ and non-adaptive HARQ have been considered.

[4-3-2. CC/IR]

Next, chase combining (CC) and incremental redundancy (IR) areconsidered as another example of a retransmission type. Hereinafter,HARQ employing CC is called HARQ with CC and HARQ employing IR is calledHARQ with IR.

For example, the controller 130 of the transmitting station 100 maycontrol the wireless communication unit 110 to employ CC as aretransmission process type. In a non-orthogonal multi-access systemsuch as IDMA, the receiving station 200 repeats a detection process anda decoding process in many cases. Accordingly, the receiving station 200may use a bit log likelihood ratio (LLR) acquired from signals that havereceived until the previous transmission for interference cancelationand the like in a process of initially detecting retransmitted signalswhen the transmitting station 100 employs CC. Of course, the controller130 may control the wireless communication unit 110 to employ IR as aretransmission process type. In IR, however, a coding bit sequenceselected for retransmission may be different whenever retransmission isperformed, even when the TBs are originally identical. Accordingly, whenthe transmitting station 100 employs IR, it is difficult for thereceiving station 200 to use a result of decoding of signals received upto the previous transmission in a process of initially detectingretransmitted signals.

Hereinafter, an example of a retransmission type decision process willbe described with reference to FIG. 21.

FIG. 21 is a flowchart illustrating an example of the flow of aretransmission type decision process executed in the transmittingstation 100 according to the present embodiment.

As illustrated in FIG. 21, first of all, it is determined whether a CWor a TB that is a transmission target is a retransmitted CW or TB instep S802.

When it is determined that the CW or TB is a retransmitted CW or TB(S802/YES), the controller 130 determines whether to use IDMA totransmit the target CW or TB in step S804. For example, the controller130 may determine that IDMA is used in the case of one-to-multiplecommunication and determine that IDMA is not used in the case ofone-to-one communication.

When it is determined that IDMA is used (S804/YES), the controller 130determines that HARQ with CC is employed in step S806.

On the other hand, when it is determined that IDMA is not used(S804/NO), the controller 130 determines that HARQ with IR is employedin step S808.

Furthermore, when it is determined that the target CW or TB is initiallytransmitted (S802/NO), the controller 130 determines that HARQ is notemployed in step S810.

Although the controller 130 employs CC when IDMA is used forretransmission and employs IR when IDMA is not used in the abovedescription, CC may be employed in both cases. Furthermore, thecontroller 130 may use other determination criteria for determination instep S804. For example, the controller 130 may employ CC when anon-orthogonal multi-access system is used for retransmission and employIR in other cases. In addition, the controller 130 may employ CC when atleast part of the retransmitted CW or TB is transmitted and received inthe same resources as other CWs or TBs and employ IR when the CW or TBis transmitted and received in different resources.

[4-3-3. Execution/Non-Execution of Interleave]

The controller 130 of the transmitting station 100 may control whetherto perform wireless communication using IDMA depending on whether atransmission sequence is a retransmitted sequence. Specifically, thecontroller 130 may switch between execution of an interleave process andnon-execution of the interleave process in response to whether a CW isretransmitted or not. It is desirable that a relation betweenretransmission/initial transmission and execution/non-execution ofinterleave be previously shared between the transmitting station 100 andthe receiving station 200. Non-execution of an interleave process may beexecution of an interleave process using an interleaver having an inputsequence and an output sequence which are identical to each other.

For example, when the transmitted sequence is a retransmitted sequence,the controller 130 may control the wireless communication unit 110 toperform wireless communication using IDMA. When the transmissionsequence is an initially transmitted sequence, the controller 130 maycontrol the wireless communication unit 110 to perform wirelesscommunication without using IDMA. Here, the controller 130 may controlwhether to perform wireless communication using IDMA depending on thenumber of receiving stations 200 that are retransmission targets. Forexample, the controller 130 may control the wireless communication unit110 to use IDMA when the number of receiving stations 200) that areretransmission targets is large and not to use IDMA when there is asingle receiving station 200 that is a retransmission target. In thiscase, the transmitting station 100 may switch between use of IDMA andnon-use of IDMA depending on possibility of interference in receivingstations 200.

As another control example, the controller 130 may control the wirelesscommunication unit 110 to perform wireless communication without usingIDMA when the transmission sequence is a retransmitted sequence and toperform wireless communication using IDMA when the transmission sequenceis an initially transmitted sequence.

The transmitting station 100 announces information indicating whetherthe transmission sequence is a retransmitted sequence to the receivingstation 200. For example, the transmitting station 100 may announcewhether an interleave is executed to the receiving station 200 bysetting a bit flag representing that the target CW is initiallytransmitted or retransmitted in a target control channel. For example, anew data indicator (NDI) in downlink control information (DCI) in acontrol channel may be an example of the bit flag. This is effectivewhen the relation between retransmission/initial transmission andexecution/non-execution of interleave is shared between the transmittingstation 100 and the receiving station 200. In addition, the transmittingstation 100 may set a bit flag directly indicating execution ornon-execution of interleave instead of or in addition to theaforementioned bit flag.

When the CW interleaver 118 of the wireless communication unit 110 is toformed in multiple stages as illustrated in FIG. 17, the controller 130may switch between execution and non-execution of an interleave processthrough each sub-interleaver, as illustrated in FIG. 22.

FIG. 22 is a flowchart illustrating an example of the flow of a processof switching between execution and non-execution of an interleaveprocess, executed in the transmitting station 100 according to thepresent embodiment.

As illustrated in FIG. 22, first of all, it is determined whether a CWthat is a transmission target is an initially transmitted CW in stepS902.

When it is determined that the CW is initially transmitted (S902/YES),the controller 130 determines that a predetermined interleave process isexecuted in step S904. For example, the controller 130 determines thatan interleave process is performed by a target sub-interleaver (e.g.,the first-stage sub-interleaver 1181 illustrated in FIG. 17) from amonga plurality of sub-interleavers included in the CW interleaver 118.

Subsequently, the controller 130 generates control informationindicating that the predetermined interleaver process has been executedin step S906. For example, the controller 130 sets a flag indicatingthat the target CW is initially transmitted or a flag indicating thatthe predetermined interleave process has been executed in a controlchannel corresponding to the target CW.

On the other hand, when it is determined that the CW is retransmitted(S902/NO), the controller 130 determines that the predeterminedinterleave process is not executed in step S908.

Then, the controller 130 generates control information indicating thatthe predetermined interleaver process has not been executed in stepS910. For example, the controller 130 sets a flag indicating that thetarget CW is retransmitted or a flag indicating that the predeterminedinterleave process has not been executed in the control channelcorresponding to the target CW.

The flow described above may be repeated for each of sub-interleaversformed in multiple stages. During repetition of the flow, adetermination criterion 16 related to any parameter shown in the abovetable 3, for example, other than the criterion for determination ofwhether the CW is initially transmitted or not may be employed as thedetermination criterion in step S902. Furthermore, steps S904 and S906may be switched with steps S908 and S910.

When the CW interleaver 118 of the wireless communication unit 110 isformed in multiple stages, as illustrated in FIG. 18, the controller 130may switch interleave process by sub-interleavers, as illustrated inFIG. 23.

FIG. 23 is a flowchart illustrating an example of the flow of a processof switching between execution and non-execution of an interleaveprocess, executed in the transmitting station 100 according to thepresent embodiment.

As illustrated in FIG. 23, first of all, it is determined whether a CWthat is a transmission target is an initially transmitted CW in stepS1002.

When it is determined that the CW is initially transmitted (S1002/YES),the controller 130 determines that a predetermined interleave process Ais executed in step S1004. For example, the controller 130 determinesthat an interleave process is executed by any sub-interleaver (e.g., thefirst-stage sub-interleaver 1181A illustrated in FIG. 18) in acombination of a plurality of sub-interleavers included in each stage ofthe CW interleaver 118.

Subsequently, the controller 130 generates control informationindicating that the predetermined interleaver process A has beenexecuted in step S1006. For example, the controller 130 sets a flagindicating that the target CW is initially transmitted or a flagindicating that the predetermined interleave process A has been executedin a control channel corresponding to the target CW.

On the other hand, when it is determined that the CW is retransmitted(S1002/NO), the controller 130 determines that a predeterminedinterleave process B is executed in step S1008. For example, thecontroller 130 determines that an interleave process is executed by asub-interleaver different from the sub-interleaver selected in stepS1004 (e.g., the first-stage sub-interleaver 1181B illustrated in FIG.18) in a combination of a plurality of sub-interleavers included in eachstage of the CW interleaver 118.

Next, the controller 130 generates control information indicating thatthe predetermined interleaver process B has been executed in step S1010.For example, the controller 130 sets a flag indicating that the targetCW is retransmitted or a flag indicating that the predeterminedinterleave process B has been executed in the control channelcorresponding to the target CW.

The flow described above may be repeated for each of combinations ofsub-interleavers formed in multiple stages. During repetition of theflow, a determination criterion related to any parameter other than thecriterion for determination of whether the CW is initially transmittedor not may be employed as the determination criterion in step S1002.According to the flow, the transmitting station 100 can employ anappropriate interleave pattern according to retransmission, therebyfurther improving transmission quality and reception quality inretransmission.

The transmitting station 100 has been described. When execution andnon-execution of an interleave process are switched in the transmittingstation, as described above, the receiving station 200 employsdeinterleave setting corresponding thereto. Hereinafter, a deinterleavesetting control process in the receiving station 200 will be describedwith reference to FIG. 24.

FIG. 24 is a flowchart illustrating an example of the flow of adeinterleave setting control process executed in the receiving station200 according to the present embodiment. This flow is based on theassumption that the transmitting station 100 switches between executionand non-execution of an interleave process by each sub-interleaver inresponse to whether the target CW is initially transmitted or not, asillustrated in FIG. 22.

As illustrated in FIG. 24, first of all, the controller 230 acquirescontrol information in step S1102. For example, the wirelesscommunication unit 110 receives control information transmitted from aneNB using a control channel, decodes the control information and outputsthe control information to the controller 230.

Subsequently, the controller 230 acquires an NDI in step S1104. Then,the controller 230 determines whether a flag of the NDI is set in stepS1106.

When it is determined that the flag of the NDI is set (S1106/YES), thecontroller 230 determines that the target CW is initially transmitted instep S1108. Thereafter, the controller 230 determines that apredetermined interleave process has been performed on the target CW instep S1110.

On the other hand, when it is determined that the flag of the NDI is notset (S1106/NO), the controller 230 determines that the target CW isretransmitted in step S1112. Subsequently, the controller 230 determinesthat a predetermined interleave process has not been performed on thetarget CW in step S1114.

Then, the controller 230 applies corresponding deinterleave setting instep S1116.

The flow described above may be repeated for each of sub-interleaversformed in multiple stages at the side of the transmitting station 100.In repetition of the flow, a determination criterion related to anyparameter other than the criterion of determination of whether the flagof the NDI is set may be employed as the determination criterion in stepS1106.

[4-4. Combination with Other Multiplexing Methods or Other MultipleAccess Methods]

[4-4-1. Example of Configuration of Transmitting Station]

The wireless communication system 1 may combine IDMA with othermultiplexing methods or other multiple access methods. Here, aconfiguration of the transmitting station 100 when IDMA is combined withother multiplexing methods or other multiple access methods will bedescribed as an example with reference to FIGS. 25 and 26.

FIG. 25 is a block diagram illustrating an example of a logicalconfiguration of the wireless communication unit 110 of the transmittingstation 100 according to the present embodiment. FIG. 25 shows anexample of a configuration when IDMA, OFDM and MIMO are combined.

As illustrated in FIG. 25, the wireless communication unit 110 includesa CRC coding unit 1101, an FEC coding unit 1102, a CW interleaver 1103,a modulation mapper 1104, a layer mapper 1105, a precoder 1106, aresource element mapper 1107, an OFDM signal generator 1108, an analogRF 1109 and a PHY layer controller 1110. The FEC coding unit 1102 mayinclude the CB segmentation unit 112 to the CB connecting unit 116illustrated in FIG. 10. The OFDM signal generator 1108 may have afunction of performing an inverse fast Fourier transform (IFFT) and afunction of adding a cyclic prefix (CP). A parallel number shown in thefigure indicates the number of parallel processes that are performed.For example, the CRC coding unit 1101 performs a number of CRC codingprocesses corresponding to the number of TBs in parallel. The PHY layercontroller 1110 inputs a corresponding parameter to each element of thewireless communication unit 110 on the basis of control informationacquired from a control channel, for example. For example, the PHY layercontroller 1110 inputs parameters for a coding rate and rate matching tothe FEC coding unit 1102. In addition, the PHY layer controller 1110inputs interleave setting to the CW interleaver 1103. Furthermore, thePHY layer controller 1110 inputs a parameter for modulation to themodulation mapper 1104. The PHY layer controller 1110 inputs a parameterfor the number of layers to the layer mapper 1105. In addition, the PHYlayer controller 1110 inputs a parameter for a codebook to the precoder1106. Furthermore, the PHY layer controller 1110 inputs a parameter forresource scheduling to the resource element mapper 1107.

It is desirable that the CW interleaver 1103 perform an interleaveprocess prior to execution of a digital modulation process such as PSKor QAM. Accordingly, the CW interleaver 1103 is installed before themodulation mapper 1104 that performs the digital modulation process, asillustrated in FIG. 25. The layer mapper 1105 maps a signal afterdigital modulation to one or more spatial layers for MIMO. Furthermore,the precoder 1106 maps the one or more spatial layer signals to a numberof signals corresponding to the number of antennas or the number ofantenna ports. In addition, the resource element mapper 1107 arrangessignal points to resource blocks and subcarriers for each antennasignal. The resource element mapper 1107 corresponds to a schedulingfunction in OFDMA. Then, the OFDM signal generator 1108 performs IFFT toadd a cyclic prefix (CP) for as a measure for an inter-symbolinterference (ISI). The OFDM signal generator 1108 corresponds tomodulation in OFDMA. In addition, the analog RF 1109 performs ADconversion, frequency conversion and the like to transmit a wirelesssignal.

Meanwhile, the controller 130 may control an FEC coding rate, aninterleave length, an interleave pattern, a digital modulation method,the number of layers, a precoder, scheduling and the like on the basisof parameters designated through the control channel.

FIG. 26 is a block diagram illustrating an example of a logicalconfiguration of the wireless communication unit 110 of the transmittingstation 100 according to the present embodiment. FIG. 26 shows anexample of a configuration when IDMA, SC-FDMA and MIMO are combined. Thewireless communication unit 110 illustrated in FIG. 26 additionallyincludes an FFT unit 1111 performing an FFT in addition to theconfiguration example illustrated in FIG. 25 and has an SC-FDMA signalgenerator 1112 instead of the OFDM signal generator 1108.

[4-4-2. Radio Resources Available for Data Transmission]

The quantity of radio resources available for data transmission (e.g.,the number N_(RE) of resource elements) may vary according to a usedmultiplexing method or multiple access method. Accordingly, theinterleave length may also vary according to a used multiplexing methodor multiple access method. Therefore, the transmitting station 100calculates the number N_(RE) of resource element available for datatransmission depending on the used multiplexing method or multipleaccess method.

FIG. 27 is an explanatory diagram of a resource grid of OFDMA. FIG. 27is an enlarged view of a part of a resource grid in which the verticaldirection corresponds to a frequency direction (physical resource block(PRB)) and the horizontal direction corresponds to a time direction(subframe). As illustrated in FIG. 27, resource elements includeelements for a reference signal, elements for a synchronization signal,elements for a notification signal, elements for a control signal andthe like in addition to elements for data transmission (PDSCH). Thenumber and arrangement of such resource elements may vary depending onallocation of radio resources and the like. Accordingly, thetransmitting station 100 calculates the number N_(RE) of resourceelements available for data transmission on the basis of allocationinformation of radio resources.

For example, the controller 130 of the transmitting station 100calculates the number N_(RE) of resource elements available for datatransmission using the following formula.

$\begin{matrix}\left\lbrack {{Math}.\mspace{14mu} 10} \right\rbrack & \; \\{N_{RE} = {\sum\limits_{r \in R}\left( {N_{{RE},r} - N_{{RS},r} - N_{{CCH},r} - N_{{BCH},r} - N_{{SS},r}} \right)}} & {{Formula}\mspace{14mu} 10}\end{matrix}$

Here, R is a set of indices of resource blocks allocated to a certainuser. N_(RE,r) is the total number of resource elements in a resourceblock r. N_(RS,r) is the total number of elements for a reference signalin the resource block r. N_(CCH,r) is the total number of elements for acontrol channel in the resource block r. N_(BCH,r) is the total numberof elements for a broadcast channel in the resource block r. N_(SS,r) isthe total number of elements for a synchronization signal in theresource block r.

For example, when a plurality of layers are multiplexed to a user, thecontroller 130 may calculate the number N_(RE) of resource elementsavailable for data transmission using the following formula.

$\begin{matrix}{\mspace{79mu} \left\lbrack {{Math}.\mspace{14mu} 11} \right\rbrack} & \; \\{N_{RE} = {N_{M}{\sum\limits_{r \in R}\left( {N_{{RE},r} - N_{{RS},r} - N_{{CCH},r} - N_{{BCH},r} - N_{{SS},r}} \right)}}} & {{Formula}\mspace{14mu} 11}\end{matrix}$

Here, N_(M) is the number of multiplexing layers.

For example, when a spreading technology is used, the controller 130 maycalculate the number N_(RE) of resource elements available for datatransmission using the following formula.

$\begin{matrix}\left\lbrack {{Math}.\mspace{14mu} 12} \right\rbrack & \; \\{N_{RE} = {\frac{N_{M}}{SF}{\sum\limits_{r \in R}\left( {N_{{RE},r} - N_{{RS},r} - N_{{CCH},r} - N_{{BCH},r} - N_{{SS},r}} \right)}}} & {{Formula}\mspace{14mu} 12}\end{matrix}$

Here, SF (>=1) is a spreading factor. When SF=1, the formula 12 is thesame as in the case in which the spreading technology is not used(formula 11).

For example, when the number of resource elements available for datatransmission is different for each layer, the controller 130 maycalculate the number N_(RE) of resource elements available for datatransmission using the following formula.

$\begin{matrix}{\mspace{79mu} \left\lbrack {{Math}.\mspace{14mu} 13} \right\rbrack} & \; \\{N_{RE} = {\sum\limits_{l \in L}\left\{ {\frac{1}{S\; F_{l}}{\sum\limits_{r \in R_{l}}\left( {N_{{RE},r,l} - N_{{RS},r,l} - N_{{CCH},r,l} - N_{{BCH},r,l} - N_{{SS},r,l}} \right)}} \right\}}} & {{Formula}\mspace{14mu} 13}\end{matrix}$

Here, L is a set of indices of multiple layers allocated to a certainuser.

The layers described above may be spatial layers such as MIMO or spatialdivision multiplexing (SDM) layers. In addition, the layers describedabove may be spreading code layers of code division multiple access(CDMA) or sparse code multiple access (SCMA), codeword layers fornon-orthogonal multiple access, superposition code layers or codewordlayers after an interleave process in IDMA, for example.

[4-5. Processing of Physical Layer in Receiving Station] (BasicConfiguration of Wireless Communication Unit 210)

FIG. 28 is a block diagram illustrating an example of a logicalconfiguration of the wireless communication unit 210 of the receivingstation 200 according to the present embodiment. FIG. 28 illustrates anexample of a configuration of a part of the wireless communication unit210 in which a signal received from the transmitting station 100 isdecoded. As illustrated in FIG. 28, the wireless communication unit 210includes a channel estimator 211, a detector 212, a CW deinterleaver213, a CW decoder 214, a CRC decoder 215, a CW interleaver 216, a softbit buffer 217 and a PHY layer controller 218.

The channel estimator 211 estimates a state of a radio wave propagationchannel between the transmitting station 100 and the receiving station200 from a reference signal included in the received signal. The channelestimator 211 outputs channel information indicating the estimated radiowave propagation channel state to the detector 212.

The detector 212 detects a data part included in the received signalusing the channel information output from the channel estimator 211.Such a detection process corresponds to a process of separating usersignals or layer signals multiplexed in the received signal or both theuser signals and the layer signals. Hereinafter, the detector 212 iscalled a multiuser/multilayer detector 212. It is desirable thatseparated signals be output in the form of bit log likelihood ratios(LLR, e.g., values in the range of [−1 to +1]) of CWs correspondingthereto. In addition, the separated signals may be output in the form ofhard decision bits (−1 or +1) of the corresponding CWs.

A decoding process corresponding to an interleave length and aninterleave pattern used in the transmitting station 100 is performed perTB or CW for output bit values. Here, a decoding process for a TB or aCW having an index i will be described.

The CW deinterleaver 213 performs a deinterleave process usingdeinterleave setting (a deinterleave length and a deinterleave pattern)corresponding to interleave setting used in the transmitting station100. Here, the deinterleave length refers to the length of a sequenceinput to the CW deinterleaver 213. The CW deinterleaver 213 outputs thedeinterleaved CW as an input to the CW decoder 214 ((A) in the figure).

The CW decoder 214 performs an FEC decoding process on eachdeinterleaved CW. The CW decoder 214 outputs the decoded CW to the CRCdecoder 215 ((B) in the figure). In addition, when a CRC error isdetected by the CRC decoder 215, the CW decoder 214 feeds back the bitvalue of the corresponding CW ((C) in the figure). The feedback targetis the CW interleaver 216 or the soft bit buffer 217. The internalconfiguration of the CW decoder 214 will be described in detail below.

The CRC decoder 215 performs a CRC detection process on the FEC-decodedCW or TB. When a CRC error is detected, the CRC decoder 215 outputs thedecoded CW or TB.

The CW interleaver 216 performs an interleave process on the CW fed backfrom the CW decoder 214 or the soft bit buffer 217 and outputs theinterleaved CW to the multiuser/multilayer detector 212. The CWinterleaver 216 performs an interleave process using interleave settingused in the transmitting station 100 corresponding to a transmissionsource. Here, a series of signal processes through which themultiuser/multilayer detector 212 outputs the CW to the CW deinterleaver213 and receives a feedback from the CW interleaver 216 may be repeateduntil decoding succeeds. For example, the decoding process may berepeated until a CRC error of the target CW or TB is not detected or thenumber of repetitions reaches a maximum number of times. Such a repeateddecoding process is called turbo detection or a turbo decoding process.

The soft bit buffer 217 has a function of accumulating decoding resultsup to the previous reception and feeding the accumulated decodingresults back to the multiuser/multilayer detector 212 when thetransmitting station 100 performs retransmission. For example, the softbit buffer 217 accumulates the bit LLR of the CW. In addition, the softbit buffer 217 outputs decoding results up to the previous reception tothe CW interleaver 216 in a process of decoding a retransmitted signal.Accordingly, the wireless communication unit 210 can perform a decodingprocess using decoding results up to the previous reception when thetransmitting station 100 employs CC. When the transmitting station 100employs IR, the soft bit buffer 217 may output no bit LLR or output apredetermined bit LLR such as a sequence in which all bits are 0, forexample.

The PHY layer controller 218 adjusts parameters in response to controlinformation acquired from a control channel. For example, the PHY layercontroller 218 sets a parameter of each block of the wirelesscommunication unit 210 according to transmission parameters (allocationresources, a modulation method, a coding method or a decoding rate,etc.) applied to the decoding target CW or TB, transmitted through thecontrol channel. In addition, the PHY layer controller 218 acquires anFEC decoding result of the CW, TB or CB from the CW decoder 214 and aCRC detection result of the CB, TB or CB from the CRC decoder 215. ThePHY layer controller 218 controls the repeated decoding processdescribed above on the basis of the FEC decoding result and the CRCdetection result.

The wireless communication unit 210 returns an ACK response to thetransmitting station 100 corresponding to the transmission source whendecoding of the target CW or TB succeeds. On the other hand, thewireless communication unit 210 returns a NACK response to thetransmitting station 100 corresponding to the transmission source whendecoding of the target CW or TB fails. The transmitting station 100controls the retransmission process in response to the ACK response andthe NACK response.

An example of the configuration of the wireless communication unit 210has been described. Next, a basic operation process of the decodingprocess in the receiving station 200 will be described with reference toFIGS. 29 and 30.

(Basic Operation Process of Wireless Communication Unit 210)

FIGS. 29 and 30 are explanatory diagrams illustrating an example of theflow of a decoding process in the receiving station 200 according to thepresent embodiment. The flows illustrated in FIGS. 29 and 30 areconnected by symbols A and B shown in the figures.

As illustrated in FIG. 29, first of all, the PHY layer controller 218determines whether the target CW is initially detected inmultiuser/multilayer detection in step S1202. For example, the PHY layercontroller 218 determines whether the detection process target of themultiuser/multilayer detector 212 is the received signal or an outputsequence from the CW interleaver 216.

When it is determined that the target CW is initially detected(S1202/YES), the PHY layer controller 218 determines whether the targetCW is initial transmission of an HARQ in step S1204.

When it is determined that the target CW is initial transmission(S1204/YES), the PHY layer controller 218 decides not to feed a bit LLRback to the multiuser/multilayer detector 212 in step S1206. The softbit buffer 217 may output no bit LLR or output a predetermined bit LLRsuch as a sequence in which all bits are 0, for example.

When it is determined that the target CW is not initial transmission(S1204/NO), the PHY layer controller 218 determines whether aretransmitted target CW is identical to the previously transmitted CW instep S1208. For example, the PHY layer controller 218 determines thatthe retransmitted target CW is identical to the previously transmittedCW when the transmitting station 100 employs CC and determines that theretransmitted target CW is not identical to the previously transmittedCW when the transmitting station 100 employs IR.

When it is determined that the retransmitted target CW is identical tothe previously transmitted CW (S1208/YES), the PHY layer controller 218decides to use the bit LLR of HARQ corresponding to the target CW in theprevious reception as feedback to the multi-user/multi-layer detector212. Accordingly, the soft bit buffer 217 outputs the bit LLR of HARQcorresponding to the target CW in the previous reception to the CWinterleaver 216. On the other hand, when it is determined that theretransmitted target CW is not identical to the previously transmittedCW (S1208/NO), the process proceeds to step S1206.

When it is determined that the target CW is not initially detected(S1202/NO), the PHY layer controller 218 decides to use the bit LLRcorresponding to the target CW in the previous decoding as feedback tothe multiuser/multilayer detector 212 in step S1212. Accordingly, the CWdecoder 214 outputs the decoded CW to the CW interleaver 216.

Then, the CW interleaver 216 interleaves the feedback of the bit LLRcorresponding to the target CW in step S1214.

Subsequently, the multiuser/multilayer detector 212 performs amultiuser/multilayer detection process in step S1216, as illustrated inFIG. 30.

Then, the CW deinterleaver 213 deinterleaves the bit LLR of the targetCW in step S1218.

Thereafter, the CW decoder 214 decodes the target CW in step S1220.

Next, the soft bit buffer 217 preserves the bit LLR corresponding to thetarget CW output from the CW decoder 214 in step S1222.

Subsequently, the CRC decoder 215 performs a CRC check on decodingresult bits output from the CW decoder 214 in step S1224.

When a CRC error is detected (S1226/YES), the PHY layer controller 218determines whether the number of executions of the detection process bythe multiuser/multilayer detector 212 performed for the target CW so faris less than a predetermined maximum number of times in step S1228.

When it is determined that the number of executions of the detectionprocess is less than the predetermined maximum number of times(S1228/YES), the process is returned to step S1202 again and therepeated decoding process is performed.

On the other hand, when it is determined that the number of executionsof the detection process reaches the predetermined maximum number oftimes (S1228/NO), the wireless communication unit 210 returns a NACKsignal with respect to the target CW in step S1230.

When a CRC error is not detected (S1226/NO), the wireless communicationunit 210 returns an ACK signal with respect to the target CW in stepS1232.

The basic operation process of the decoding process in the receivingstation 200 has been described. The CW in the figure may be changed to aTB.

(Internal Configuration of CW Decoder 214)

Hereinafter, the internal configuration of the CW decoder 214 will bedescribed with reference to FIG. 31.

FIG. 31 is a block diagram illustrating an example of a logicalconfiguration of the CW decoder 214 according to the present embodiment.As illustrated in FIG. 31, the CW decoder 214 includes a CB segmentationunit 2140, a rate-dematching unit 2141, a HARQ combining unit 2142, anFEC decoding unit 2143, a CRC decoding unit 2144, a CB connecting unit2145, a soft bit buffer 2146, a rate-matching unit 2147 and a CBconnecting unit 2148. As illustrated in FIG. 28, the CW decoder 214 maybe a block with one input and two outputs. (A), (B) and (C) in FIG. 31respectively correspond to (A), (B) and (C) in FIG. 28. (B) of FIG. 31is an output of a CRC detection process of a decoded CW or TB and (C) ofFIG. 31 is an output for preservation by the soft bit buffer 217 andfeedback to the multiuser/multilayer detector 212.

The CB segmentation unit 2140 segments each CW separated in themultiuser/multilayer detector 212 into one or more corresponding CBs.Accordingly, the following process is a process in units of CB.

The rate-dematching unit 2141 compensates for bits punctured in thetransmitting station 100 according to a rate-dematching process.

When a processing target CB is a retransmitted CB according to HARQ, theHARQ combining unit 2142 performs a process of combining bit values(e.g., LLR) preserved up to the previous decoding process with currentlyreceived bits. The bit values are preserved in the soft bit buffer 2146.In the case of initial transmission, the HARQ combining unit 2142 doesnot perform the combining process.

The FEC decoding unit 2143 reproduces transmission bits from thereceived bits using a decoding method corresponding to FEC coding usedin the transmitting station 100. For example, the FEC decoding unit 2143uses turbo decoding when the FEC coding is turbo coding, Viterbidecoding when the FEC coding is convolutional coding, and sum-productmessage passing or belief propagation when the FEC coding is LDPCcoding.

The CRC decoding unit 2144 performs a CRC detection process for each CB.The FEC decoding unit 2143 may repeat the FEC decoding process until aCRC error is not detected or a predetermined maximum number of times isreached.

The CB connecting unit 2145 combines one or more CBs output from the CRCdecoding unit 2144 and outputs the combined CBs ((B) in the figure).

The soft bit buffer 2146 stores a bit sequence (soft bit or bit LLR)decoded by the FEC decoding unit 2143 and outputs the bit sequence tothe HARQ combining unit 2142 or the rate-matching unit 2147. Inaddition, the soft bit buffer 2146 for output to the HARQ combining unit2142 and the soft bit buffer 2146 for output to the rate-matching unit2147 may be provided separately.

The rate-matching unit 2147 performs rate matching on the CB (bit LLR)output from the FEC decoding unit 2143 or the soft bit buffer 2146.

The CB connecting unit 2148 combines one or more CBs output from therate-matching unit 2147 and outputs the combined CBs ((C) in thefigure).

(Operation Process of CW Decoder 214)

FIGS. 32 to 35 are explanatory diagrams illustrating an example of theflow of a decoding process in the receiving station 200 according to thepresent embodiment. The flows illustrated in FIGS. 32 to 34 areconnected by symbols A to F shown in the figures.

As illustrated in FIG. 32, first of all, the PHY layer controller 218determines whether one or more multiuser/multilayer detection processeshave been performed on a target CW in step S1302.

When it is determined that one or more multiuser/multilayer detectionprocesses have been performed (S1302/YES), the CB segmentation unit 2140segments the CW into one or more CBs in step S1304. This processcorresponds to the input (A) illustrated in FIG. 31. As illustrated inFIG. 32, the following process is performed for each CB.

Subsequently, the PHY layer controller 218 determines whether a resultwithout a CRC error has been acquired in reception including theprevious reception for a target CB in step S1306.

When it is determined that a result without a CRC error has beenacquired (S1306/YES), the PHY layer controller 218 considers that thetarget CB has no CRC error in step S1308.

On the other hand, when it is determined that no result without a CRCerror has been acquired (S1306/NO), the rate-dematching unit 2141performs a rate-dematching process for the bit LLR in step S1310.

Then, the PHY layer controller 218 determines whether the target CB is aCB according to retransmission of HARQ in step S1312.

When it is determined that the target CB is a retransmitted CB(S1312/YES), the HARQ combining unit 2142 acquires the bit LLR in theprevious reception from the soft bit buffer 2146 in step S1314. When itis determined that the target CB is an initially transmitted CB(S1312/NO), the process proceeds to step S1318 which will be describedbelow.

Subsequently, the HARQ combining unit 2142 combines the current targetbit LLR with the bit LLR of the previous reception in step S1316. Forexample, the HARQ combining unit 2142 may perform addition, averaging,weighted averaging or IR combination.

Thereafter, the FEC decoding unit 2143 performs FEC decoding in stepS1318.

Then, the soft bit buffer 2146 preserves soft bits (bit LLR)corresponding to a decoding result from the FEC decoding unit 2143 instep S1320.

Subsequently, the CRC decoding unit 2144 performs a CRC check fordecoding result bits from the FEC decoding unit 2143 in step S1322.

When there is a CRC error (S1324/YES), the PHY layer controller 218determines whether the number of executions of FEC decoding performedfor the target CB so far is less than a predetermined maximum number oftimes in step S1326.

When it is determined that the number of executions of FEC decodingperformed so far is less than the predetermined maximum number of times(S1326/YES), the process returns to step S1318 again and FEC decoding isrepeated.

When there is no CRC error (S1324/NO) or when it is determined that thenumber of executions of FEC decoding performed so far reaches thepredetermined maximum number of times (S1326/NO), the CB connecting unit2145 connects the one or more CBs into a CW in step S1328.

In addition, the CB connecting unit 2145 outputs the connected CW instep S1330. This corresponds to the output (B) in FIG. 31.

Next, the PHY layer controller 218 determines whether it is necessary tofeed the target CW back to the multiuser/multilayer detector 212 in stepS1332. Determination criteria in this case will be described in detailbelow with reference to FIG. 35.

When it is determined that the feedback is not necessary (S1332/NO), theprocess is ended.

When it is determined that the feedback is necessary (S1332/YES), thesoft bit buffer 2146 feeds back the bit LLR corresponding to the targetCB in step S1334. Specifically, the soft bit buffer 2146 outputs the bitLLR corresponding to the target CB to the rate-matching unit 2147.

Then, the rate-matching unit 2147 performs a rate matching process forthe target bit LLR feedback in step S1336.

Subsequently, the CB connecting unit 2148 connects bit LLR feedbacks ofthe one or more CBs into a CW in step S1338.

In addition, the CB connecting unit 2148 outputs the obtained CW in stepS1340. This corresponds to the output (C) in FIG. 31.

Meanwhile, when it is determined that multiuser/multilayer detection hasnot yet been performed on the target CW in step S1302 (S1302/NO), thePHY layer controller 218 determines whether the target CW is a CWaccording to initial transmission of HARQ in step S1342.

When it is determined that the target CW is an initially transmitted CW(S1342/YES), the soft hit buffer 2146 sets the bit LLR of the target CBto 0 and feeds back the bit LLR in step S344. Then, the process proceedsto step S1336.

On the other hand, when it is determined that the target CW is aretransmitted CW (S1342/NO), the PHY layer controller 218 determineswhether the target CW is retransmitted using HARQ with CC in step S1346.

When it is determined that the target CW is retransmitted using HARQwith CC (S1346/YES), the soft bit buffer 2146 feeds back soft bits or abit LLR preserved during the previous reception of HARQ corresponding tothe target CB in step S1348. Then, the process proceeds to step S1336.

On the other hand, when it is determined that the target CW is notretransmitted using HARQ with CC (S1346/NO), the process proceeds tostep S1344.

Next, the determination process in step S1332 will be described withreference to FIG. 35.

As illustrated in FIG. 35, first of all, the PHY layer controller 218determines ti whether the target multiuser/multilayer detector 212employs a repeated process in step S1402.

When it is determined that the target multiuser/multilayer detector 212does not employ a repeated process (S1402/NO), the PHY layer controller218 determines that feedback of the target CW is not necessary in stepS1404.

When it is determined that the target multiuser/multilayer detector 212employs a repeated process (S1402/YES), the PHY layer controller 218determines whether the number of detections by the targetmultiuser/multilayer detector 212 reaches a predetermined maximum numberof times in step S1406.

When it is determined that the number of detections reaches thepredetermined maximum number of times (S1406/YES), the process proceedsto step S1404.

On the other hand, when it is determined that the number of detectionsdoes not reach the predetermined maximum number of times (S1406/NO), thePHY layer controller 218 determines whether there is a CRC error withrespect to the target CW in step S1408.

When it is determined that there is a CRC error (S1408/YES), the PHYlayer controller 218 determines that feedback of the target CW isnecessary in step S1410.

On the other hand, when it is determined that there is no CRC error(S1408/NO), it is determined whether the target multiuser/multilayerdetector 212 requires feedback of another CW for detection of a certainCW in step S1412.

When it is determined that feedback of another CW is required(S1412/YES), it is determined whether there is a CRC error with respectto a CW other than the target CW in step S1414.

When it is determined that there is a CRC error with respect to a CWother than the target CW (S1414/YES), the process proceeds to stepS1410.

On the other hand, when it is determined that feedback of another CW isnot required (S1412/NO) or when it is determined that there is no CRCerror with respect to a CW other than the target CW (S1414/NO), theprocess proceeds to step S1404.

The decoding process in the CW decoder 214 has been described.Incidentally, the CW in the figure may be changed to a TB.

[4-6. Deinterleave Setting]

The receiving station 200 according to the present embodiment performs adeinterleave process using deinterleave setting corresponding to theinterleave setting used by the transmitting station 100. Accordingly,the controller 230 of the receiving station 200 decides deinterleavesetting corresponding to the interleave length used by the transmittingstation 100. Therefore, the receiving station 200 can correctly detectand decode a received signal.

The controller 230 decides a deinterleave length through a processcorresponding to the interleave length decision process in thetransmitting station 100. For example, the controller 230 decides adeinterleave length G on the basis of the number N_(RE) of resourceelements and the bit multiplex number Q_(m) per resource element usedfor data transmission by the transmitting station 100. The sequence ofthis decision process may be changed depending on the type of thereceiving station 200. Hereinafter, an example of the deinterleavelength decision process depending on the type of the receiving station200 will be described.

(Relation with Receiving Station Type)(A) Receiving Station to which Radio Resources to be Received areAllocated by Other Devices

For example, the receiving station 200 is a UE in a cellular system.Hereinafter, a method of deciding the deinterleave length G will bedescribed with reference to FIG. 36.

FIG. 36 is a flowchart illustrating an example of the flow of adeinterleave length decision process executed in the receiving station200 according to the present embodiment.

First of all, the wireless communication unit 210 receives and decodescontrol information in step S1502. For example, the wirelesscommunication unit 210 receives and decodes control informationtransmitted from an eNB using a control channel.

Then, the controller 230 acquires information about radio resourcesallocated for reception of the receiving station 200 in step S1504. Thisinformation may be included in the control information, for example.

Thereafter, the controller 230 acquires the number N_(RE) of resourceelements to be received thereby in step S1506. For example, thecontroller 230 acquires information indicating the number N_(RE) ofresource elements used for data transmission by the transmitting station100 from the control information. For example, when the number ofallocations of resources in the frequency direction is previouslydetermined such as a case in which the entire band is allocated to thetransmitting station 100, the processes in steps S1504 and S1506 may beomitted.

Subsequently, in step S1508, the controller 230 acquires informationindicating a modulation scheme used for transmission to the receivingstation 200 from the control information, received in step S1502. Theinformation indicating the modulation scheme may be information thatdirectly designates the modulation scheme, such as a CQI in LTE. Inaddition, the information indicating the modulation scheme may beinformation that indirectly designates the modulation scheme, such as anMCS in LTE. It is desirable that the information indicating themodulation scheme be previously specified in the wireless communicationsystem 1.

Then, the controller 230 acquires the bit number Q_(m) per resourceelement, used for transmission to the receiving station 200 in stepS1510. For example, the controller 230 acquires the bit number Q_(m) perresource element from the modulation scheme indicated by the informationacquired in step S1508. When the control information includesinformation indicating the bit number Q_(m) per resource element, thecontroller 230 may acquire the bit number Q_(m) per resource elementfrom the control information.

Thereafter, the controller 230 decides the deinterleave length G in stepS1512 For example, the controller 230 decides the deinterleave length Gas G=N_(RE)×Q_(m).

(B) Receiving Station Allocating (or Deciding) Radio Resources to beReceived by Itself

For example, the receiving station 200 is an eNB in a cellular system.In addition, the receiving station 200 is a device of the wirelesscommunication system 1 having no radio resource allocation, for example.Hereinafter, a method of deciding the deinterleave length G will bedescribed with reference to FIG. 37.

FIG. 37 is a flowchart illustrating an example of the flow of adeinterleave length decision process executed in the receiving station200 according to the present embodiment. In this flow, a processingexample when reception from a user i is performed will be described onthe assumption of one-to-on reception. In the case of multiple-to-onereception, there are multiple user indices i.

As illustrated in FIG. 37, first of all, the controller 230 acquiresinformation related to radio resources used for the receiving station200 to receive signals from the user i in step S1602.

Subsequently, the controller 230 acquires the number N_(RE) of resourceelements for receiving signals from the user i in step S1604. When thenumber of resources allocated in the frequency direction is previouslydecided, the processes in steps S1602 and S1604 may be omitted.

Then, the controller 230 acquires information indicating a modulationscheme used by the user i for transmission in step S1606.

Thereafter, the controller 230 acquires the bit number Q_(m) perresource elements used by the user i for transmission in step S1608.

Then, the controller 230 decides the deinterleave length G in stepS1610. For example, the controller 130 decides the deinterleave length Gas G=N_(RE)×Q_(m).

An example of the flow the deinterleave length decision process has beendescribed.

(Relation with HARQ Type)

Next, an example of a deinterleave length decision process depending onan HARQ type used in the transmitting station 100 will be described withreference to FIG. 38.

FIG. 38 is a flowchart illustrating an example of the flow of adeinterleave length decision process executed in the receiving station200 according to the present embodiment.

As illustrated in FIG. 38, first of all, the controller 230 determineswhether a target TB is an initially received TB in step S1702.

When it is determined that the target TB is an initially received TB(S1702/YES), the controller 230 decides a deinterleave length through aprocedure for initial reception in step S1704. Here, the procedure forinitial reception refers to the sequences described as examples in FIGS.36 and 37.

When it is determined that the target TB is not an initially received TB(S1702/NO), the controller 230 determines whether retransmission usingadaptive HARQ has been performed in step S1706.

When it is determined that retransmission using adaptive HARQ has beenperformed (S1706/YES), the process proceeds to step S1704 and thecontroller 230 decides the deinterleave length through the procedure forinitial reception.

On the other hand, when it is determined that retransmission usingnon-adaptive HARQ has been performed (S1706/NO), the controller 230determines whether the number N_(RE) of resource elements used for datatransmission by the transmitting station 100 differs from that in theprevious reception in step S1708.

When it is determined that the number N_(RE) of resource elementsdiffers from that in the previous reception (S1708/YES), the processproceeds to step S1704 and the controller 230 decides the deinterleavelength through the procedure for initial transmission.

On the other hand, when it is determined that the number N_(RE) ofresource elements is identical to that in the previous reception(S1708/NO), the controller 230 employs the same deinterleave length asin the previous reception again in step S1710.

[4-7. Control Information]

Hereinafter, specific examples of control information (informationelement) transmitted and received between devices included in thewireless communication system 1 will be described.

As an example, control information announced by an eNB to other devicesis shown in the following table 4. The control information shown inTable 4 may be announced by the eNB to a UE, may be announced using acontrol channel such as a PDCCH and may be announced to any otherdevices. Here, the eNB has a scheduling function of allocating aresource block, a modulation method, a coding method and the like, andthe operation of the UE is controlled by an eNB corresponding to anaccess target. In addition, the eNB may perform control related to aninterleave process and a deinterleave process like scheduling. “Targetcommunication” in Table 4 may be any of downlink, uplink and D2Dcommunication.

TABLE 4 Information Element Description Control Information FormatRepresents format of control information. Link Format Representsdownlink/uplink/D2D, etc. Duplex Format Represents FDD/TDD. FrameConfiguration Format Represents TDD frame configuration format. ResourceBlock Allocation Represents positions of resource blocks allocated totarget communication (and TB or CW). Modulation and Coding SetRepresents modulation and coding schemes to be used in targetcommunication (and TB or CW). HARQ Process Number Represents HARQprocess number of target communication (and TB or CW). New DataIndicator Represents whether target communication (and TB or CW) is new(initial transmission). Redundancy Version Represents redundancy versionof target communication (and TB or CW)(related to HARQ with IR).Scrambler/Interleaver Format Represents format (pattern) of frequencyband converter/interleaver to be used in target communication (and TB orCW). Interleaver Offset Indicator Represents offset value of interleaverto be used in target communication (and TB or CW). ACK/NACK FlagFundamentally represents success/failure of communication (and TB or CW)prior to transmission of this information.

As another example, control information announced by a UE to otherdevices is shown in the following table 5. The control information shownin Table 5 may be announced by a UE controlled by an eNB to the eNB orannounced to any other devices.

TABLE 5 Information Element Description Control Information FormatRepresents format of control information. HARQ Process Number RepresentsHARQ process number of target communication (and TB or CW). New DataIndicator Represents whether target communication (and TB or CW) is new(initial transmission). Redundancy Version Represents redundancy versionof target communication (and TB or CW)(related to HARQ with IR).Scrambler/Interleaver Format Represents format (pattern) of frequencyband converter/interleaver to be used in target communication (and TB orCW). Interleaver Offset Indicator Represents offset value of interleaverto be used in target communication (and TB or CW). ACK/NACK FlagFundamentally represents success/failure of communication (and TB or CW)prior to transmission of this information. Interleaver Capability FlagRepresents possibility of supporting IDMA.

The control information shown in Table 5 does not include theinformation related to scheduling, included in the control informationshown in Table 4, and includes information indicating possibility ofsupporting IDMA. An eNB that has received the control information shownin Table 5 can perform more efficient scheduling in consideration ofboth a UE capable of supporting IDMA and a UE incapable of supportingIDMA using the information indicating possibility of supporting IDMA.

5. APPLICATION EXAMPLES

The technology of the present disclosure is applicable to variousproducts. For example, the communication control device 300 may berealized as any type of server such as a tower server, a rack server,and a blade server. The communication control device 300 may be acontrol module (such as an integrated circuit module including a singledie, and a card or a blade that is inserted into a slot of a bladeserver) mounted on a server.

For example, a transmitting station 100 or a receiving station 200 maybe realized as any type of evolved Node B (eNB) such as a macro eNB, anda small eNB. A small eNB may be an eNB that covers a cell smaller than amacro cell, such as a pico eNB, micro eNB, or home (femto) eNB. Instead,the transmitting station 100 or the receiving station 200 may berealized as any other types of base stations such as a NodeB and a basetransceiver station (BTS). The transmitting station 100 or the receivingstation 200 may include a main body (that is also referred to as a basestation device) configured to control wireless communication, and one ormore remote radio heads (RRH) disposed in a different place from themain body. Additionally, various types of terminals to be discussedlater may also operate as the transmitting station 100 or the receivingstation 200 by temporarily or semi-permanently executing a base stationfunction.

For example, the transmitting station 100 or the receiving station 200may be realized as a mobile terminal such as a smartphone, a tabletpersonal computer (PC), a notebook PC, a portable game terminal, aportable/dongle type mobile router, and a digital camera, or anin-vehicle terminal such as a car navigation device. The transmittingstation 100 or the receiving station 200 may also be realized as aterminal (that is also referred to as a machine type communication (MTC)terminal) that performs machine-to-machine (M2M) communication.Furthermore, the transmitting station 100 or the receiving station 200may be a communication module (such as an integrated circuit moduleincluding a single die) mounted on each of the terminals.

5.1. Application Example Regarding a Communication Control Device

FIG. 39 is a block diagram illustrating an example of a schematicconfiguration of a server 700 to which the technology of the presentdisclosure may be applied. The server 700 includes a processor 701, amemory 702, a storage 703, a network interface 704, and a bus 706.

The processor 701 may be, for example, a central processing unit (CPU)or a digital signal processor (DSP), and controls functions of theserver 700. The memory 702 includes random access memory (RAM) and readonly memory (ROM), and stores a program that is executed by theprocessor 701 and data. The storage 703 may include a storage mediumsuch as a semiconductor memory and a hard disk.

The network interface 704 is a wired communication interface forconnecting the server 700 to a wired communication network 705. Thewired communication network 705 may be a core network such as an EvolvedPacket Core (EPC), or a packet data network (PDN) such as the Internet.

The bus 706 connects the processor 701, the memory 702, the storage 703,and the network interface 704 to each other. The bus 706 may include twoor more buses (such as a high speed bus and a low speed bus) each ofwhich has different speed.

The server 700 shown in FIG. 39 may include functions as thecommunication control device 300. In the server 700, the communicationunit 310, the storage unit 320, and the controller 330 described withreference to FIG. 8 may be implemented by the processor 701.

5-2. Application Examples Regarding Base Stations First ApplicationExample

FIG. 40 is a block diagram illustrating a first example of a schematicconfiguration of an eNB to which the technology of the presentdisclosure may be applied. An eNB 800 includes one or more antennas 810and a base station device 820. Each antenna 810 and the base stationdevice 820 may be connected to each other via an RF cable.

Each of the antennas 810 includes a single or multiple antenna elements(such as multiple antenna elements included in an MIMO antenna), and isused for the base station device 820 to transmit and receive wirelesssignals. The eNB 800 may include the multiple antennas 810, asillustrated in FIG. 40. For example, the multiple antennas 810 may becompatible with multiple frequency bands used by the eNB 800. AlthoughFIG. 40 illustrates the example in which the eNB 800 includes themultiple antennas 810, the eNB 800 may also include a single antenna810.

The base station device 820 includes a controller 821, a memory 822, anetwork interface 823, and a wireless communication interface 825.

The controller 821 may be, for example, a CPU or a DSP, and operatesvarious functions of a higher layer of the base station device 820. Forexample, the controller 821 generates a data packet from data in signalsprocessed by the wireless communication interface 825, and transfers thegenerated packet via the network interface 823. The controller 821 maybundle data from multiple base band processors to generate the bundledpacket, and transfer the generated bundled packet. The controller 821may have logical functions of performing control such as radio resourcecontrol, radio bearer control, mobility management, admission control,and scheduling. The control may be performed in corporation with an eNBor a core network node in the vicinity. The memory 822 includes RAM andROM, and stores a program that is executed by the controller 821, andvarious types of control data (such as a terminal list transmissionpower data, and scheduling data).

The network interface 823 is a communication interface for connectingthe base station device 820 to a core network 824. The controller 821may communicate with a core network node or another eNB via the networkinterface 823. In that case, the eNB 800, and the core network node orthe other eNB may be connected to each other through a logical interface(such as an SI interface and an X2 interface). The network interface 823may also be a wired communication interface or a wireless communicationinterface for radio backhaul. If the network interface 823 is a wirelesscommunication interface, the network interface 823 may use a higherfrequency band for wireless communication than a frequency band used bythe wireless communication interface 825.

The wireless communication interface 825 supports any cellularcommunication scheme such as Long Term Evolution (LTE) and LTE-Advanced,and provides radio connection to a terminal positioned in a cell of theeNB 800 via the antenna 810. The wireless communication interface 825may typically include, for example, a baseband (BB) processor 826 and anRF circuit 827. The BB processor 826 may perform, for example,encoding/decoding, modulating/demodulating, andmultiplexing/demultiplexing, and performs various types of signalprocessing of layers (such as L1, medium access control (MAC), radiolink control (RLC), and a packet data convergence protocol (PDCP)). TheBB processor 826 may have a part or all of the above-described logicalfunctions instead of the controller 821. The BB processor 826 may be amemory that stores a communication control program, or a module thatincludes a processor and a related circuit configured to execute theprogram. Updating the program may allow the functions of the BBprocessor 826 to be changed. The module may be a card or a blade that isinserted into a slot of the base station device 820. Alternatively, themodule may also be a chip that is mounted on the card or the blade.Meanwhile, the RF circuit 827 may include, for example, a mixer, afilter, and an amplifier, and transmits and receives wireless signalsvia the antenna 810.

The wireless communication interface 825 may include the multiple BBprocessors 826, as illustrated in FIG. 40. For example, the multiple BBprocessors 826 may be compatible with multiple frequency bands used bythe eNB 800. The wireless communication interface 825 may include themultiple RF circuits 827, as illustrated in FIG. 40. For example, themultiple RF circuits 827 may be compatible with multiple antennaelements. Although FIG. 40 illustrates the example in which the wirelesscommunication interface 825 includes the multiple BB processors 826 andthe multiple RF circuits 827, the wireless communication interface 825may also include a single BB processor 826 or a single RF circuit 827.

Second Application Example

FIG. 41 is a block diagram illustrating a second example of a schematicconfiguration of an eNB to which the technology of the presentdisclosure may be applied. An eNB 830 includes one or more antennas 840,a base station device 850, and an RRH 860. Each antenna 840 and the RRH860 may be connected to each other via an RF cable. The base stationdevice 850 and the RRH 860 may be connected to each other via a highspeed line such as an optical fiber cable.

Each of the antennas 840 includes a single or multiple antenna elements(such as multiple antenna elements included in an MIMO antenna), and isused for the RRH 860 to transmit and receive wireless signals. The eNB830 may include the multiple antennas 840, as illustrated in FIG. 41.For example, the multiple antennas 840 may be compatible with multiplefrequency bands used by the eNB 830. Although FIG. 41 illustrates theexample in which the eNB 830 includes the multiple antennas 840, the eNB830 may also include a single antenna 840.

The base station device 850 includes a controller 851, a memory 852, anetwork interface 853, a wireless communication interface 855, and aconnection interface 857. The controller 851, the memory 852, and thenetwork interface 853 are the same as the controller 821, the memory822, and the network interface 823 described with reference to FIG. 40.

The wireless communication interface 855 supports any cellularcommunication scheme such as LTE and LTE-Advanced, and provides wirelesscommunication to a terminal positioned in a sector corresponding to theRRH 860 via the RRH 860 and the antenna 840. The wireless communicationinterface 855 may typically include, for example, a BB processor 856.The BB processor 856 is the same as the BB processor 826 described withreference to FIG. 40, except the BB processor 856 is connected to the RFcircuit 864 of the RRH 860 via the connection interface 857. Thewireless communication interface 855 may include the multiple BBprocessors 856, as illustrated in FIG. 41. For example, the multiple BBprocessors 856 may be compatible with multiple frequency bands used bythe eNB 830. Although FIG. 41 illustrates the example in which thewireless communication interface 855 includes the multiple BB processors856, the wireless communication interface 855 may also include a singleBB processor 856.

The connection interface 857 is an interface for connecting the basestation device 850 (wireless communication interface 855) to the RRH860. The connection interface 857 may also be a communication module forcommunication in the above-described high speed line that connects thebase station device 850 (wireless communication interface 855) to theRRH 860.

The RRH 860 includes a connection interface 861 and a wirelesscommunication interface 863.

The connection interface 861 is an interface for connecting the RRH 860(wireless communication interface 863) to the base station device 850.The connection interface 861 may also be a communication module forcommunication in the above-described high speed line.

The wireless communication interface 863 transmits and receives wirelesssignals via the antenna 840. The wireless communication interface 863may typically include, for example, the RF circuit 864. The RF circuit864 may include, for example, a mixer, a filter, and an amplifier, andtransmits and receives wireless signals via the antenna 840. Thewireless communication interface 863 may include multiple RF circuits864, as illustrated in FIG. 41. For example, the multiple RF circuits864 may support multiple antenna elements. Although FIG. 41 illustratesthe example in which the wireless communication interface 863 includesthe multiple RF circuits 864, the wireless communication interface 863may also include a single RF circuit 864.

The eNB 800 and the eNB 830 shown in FIGS. 40 and 41 may includefunctions as the transmitting station 100. For example, in the eNB 800and the eNB 830, the wireless communication unit 110, the storage unit120, and the controller 130 described with reference to FIG. 6 may beimplemented by the wireless communication interface 855 and the wirelesscommunication interface 855 and/or the wireless communication interface863. Alternatively, at least some of these constituent elements may beimplemented by the controller 821 and the controller 851.

Further, the eNB 800 and the eNB 830 shown in FIGS. 40 and 41 mayinclude functions as the receiving station 200. For example, in the eNB800 and the eNB 830, the wireless communication unit 210, the storageunit 220, and the controller 230 described with reference to FIG. 7 maybe implemented by the wireless communication interface 855 and thewireless communication interface 855 and/or the wireless communicationinterface 863. Alternatively, at least some of these constituentelements may be implemented by the controller 821 and the controller851.

The eNB 800 and the eNB 830 shown in FIGS. 40 and 41 may includefunctions as the communication control device 300. For example, in theeNB 800 and the eNB 830, the wireless communication unit 310, thestorage unit 320, and the controller 330 described with reference toFIG. 8 may be implemented by the wireless communication interface 855and the wireless communication interface 855 and/or the wirelesscommunication interface 863. Alternatively, at least some of theseconstituent elements may be implemented by the controller 821 and thecontroller 851.

5-3. Application Examples Regarding Terminal Devices First ApplicationExample

FIG. 42 is a block diagram illustrating an example of a schematicconfiguration of a smartphone 900 to which the technology of the presentdisclosure may be applied. The smartphone 900 includes a processor 901,a memory 902, a storage 903, an external connection interface 904, acamera 906, a sensor 907, a microphone 908, an input device 909, adisplay device 910, a speaker 911, a wireless communication interface912, one or more antenna switches 915, one or more antennas 916, a bus917, a battery 918, and an auxiliary controller 919.

The processor 901 may be, for example, a CPU or a system on a chip(SoC), and controls functions of an application layer and another layerof the smartphone 900. The memory 902 includes RAM and ROM, and stores aprogram that is executed by the processor 901, and data. The storage 903may include a storage medium such as a semiconductor memory and a harddisk. The external connection interface 904 is an interface forconnecting an external device such as a memory card and a universalserial bus (USB) device to the smartphone 900.

The camera 906 includes an image sensor such as a charge coupled device(CCD) and a complementary metal oxide semiconductor (CMOS), andgenerates a captured image. The sensor 907 may include a group ofsensors such as a measurement sensor, a gyro sensor, a geomagneticsensor, and an acceleration sensor. The microphone 908 converts soundsthat are input to the smartphone 900 to audio signals. The input device909 includes, for example, a touch sensor configured to detect touchonto a screen of the display device 910, a keypad, a keyboard, a button,or a switch, and receives an operation or an information input from auser. The display device 910 includes a screen such as a liquid crystaldisplay (LCD) and an organic light-emitting diode (OLED) display, anddisplays an output image of the smartphone 900. The speaker 911 convertsaudio signals that are output from the smartphone 900 to sounds.

The wireless communication interface 912 supports any cellularcommunication scheme such as LTE and LTE-Advanced, and performs wirelesscommunication. The wireless communication interface 912 may typicallyinclude, for example, a BB processor 913 and an RF circuit 914. The BBprocessor 913 may perform, for example, encoding/decoding,modulating/demodulating, and multiplexing/demultiplexing, and performsvarious types of signal processing for wireless communication.Meanwhile, the RF circuit 914 may include, for example, a mixer, afilter, and an amplifier, and transmits and receives wireless signalsvia the antenna 916. The wireless communication interface 913 may alsobe a one chip module that has the BB processor 913 and the RF circuit914 integrated thereon. The wireless communication interface 912 mayinclude the multiple BB processors 913 and the multiple RF circuits 914,as illustrated in FIG. 42. Although FIG. 42 illustrates the example inwhich the wireless communication interface 913 includes the multiple BBprocessors 913 and the multiple RF circuits 914, the wirelesscommunication interface 912 may also include a single BB processor 913or a single RF circuit 914.

Furthermore, in addition to a cellular communication scheme, thewireless communication interface 912 may support another type ofwireless communication scheme such as a short-distance wirelesscommunication scheme, a near field communication scheme, and a wirelesslocal area network (LAN) scheme. In that case, the wirelesscommunication interface 912 may include the BB processor 913 and the RFcircuit 914 for each wireless communication scheme.

Each of the antenna switches 915 switches connection destinations of theantennas 916 among multiple circuits (such as circuits for differentwireless communication schemes) included in the wireless communicationinterface 912.

Each of the antennas 916 includes a single or multiple antenna elements(such as multiple antenna elements included in an MIMO antenna), and isused for the wireless communication interface 912 to transmit andreceive wireless signals. The smartphone 900 may include the multipleantennas 916, as illustrated in FIG. 42. Although FIG. 42 illustratesthe example in which the smartphone 900 includes the multiple antennas916, the smartphone 900 may also include a single antenna 916.

Furthermore, the smartphone 900 may include the antenna 916 for eachwireless communication scheme. In that case, the antenna switches 915may be omitted from the configuration of the smartphone 900.

The bus 917 connects the processor 901, the memory 902, the storage 903,the external connection interface 904, the camera 906, the sensor 907,the microphone 908, the input device 909, the display device 910, thespeaker 911, the wireless communication interface 912, and the auxiliarycontroller 919 to each other. The battery 918 supplies power to blocksof the smartphone 900 illustrated in FIG. 42 via feeder lines, which arepartially shown as dashed lines in the figure. The auxiliary controller919 operates a minimum necessary function of the smartphone 900, forexample, in a sleep mode.

The smartphone 900 shown in FIG. 42 may include functions as thetransmitting station 100. For example, in the smartphone 900, thewireless communication unit 110, the storage unit 120, and thecontroller 130 described with reference to FIG. 6 may be implemented bythe wireless communication interface 912. Alternatively, at least someof these constituent elements may be implemented by the processor 901 orthe auxiliary controller 919.

Further, the smartphone 900 shown in FIG. 42 may include functions asthe receiving station 200. For example, in the smartphone 900, thewireless communication unit 210, the storage unit 220, and thecontroller 230 described with reference to FIG. 7 may be implemented bythe wireless communication interface 912. Alternatively, at least someof these constituent elements may be implemented by the processor 901 orthe auxiliary controller 919.

Further, the smartphone 900 shown in FIG. 42 may include functions asthe communication control device 300. For example, in the smartphone900, the wireless communication unit 310, the storage unit 320, and thecontroller 330 described with reference to FIG. 8 may be implemented bythe wireless communication interface 912. Alternatively, at least someof these constituent elements may be implemented by the processor 901 orthe auxiliary controller 919.

Second Application Example

FIG. 43 is a block diagram illustrating an example of a schematicconfiguration of a car navigation device 920 to which the technology ofthe present disclosure may be applied. The car navigation device 920includes a processor 921, a memory 922, a global positioning system(GPS) module 924, a sensor 925, a data interface 926, a content player927, a storage medium interface 928, an input device 929, a displaydevice 930, a speaker 931, a wireless communication interface 933, oneor more antenna switches 936, one or more antennas 937, and a battery938.

The processor 921 may be, for example, a CPU or a SoC, and controls anavigation function and another function of the car navigation device920. The memory 922 includes RAM and ROM, and stores a program that isexecuted by the processor 921, and data.

The GPS module 924 uses GPS signals received from a GPS satellite tomeasure a position (such as latitude, longitude, and altitude) of thecar navigation device 920. The sensor 925 may include a group of sensorssuch as a gyro sensor, a geomagnetic sensor, and a barometric sensor.The data interface 926 is connected to, for example, an in-vehiclenetwork 941 via a terminal that is not shown, and acquires datagenerated by the vehicle, such as vehicle speed data.

The content player 927 reproduces content stored in a storage medium(such as a CD and a DVD) that is inserted into the storage mediuminterface 928. The input device 929 includes, for example, a touchsensor configured to detect touch onto a screen of the display device930, a button, or a switch, and receives an operation or an informationinput from a user. The display device 930 includes a screen such as aLCD or an OLED display, and displays an image of the navigation functionor content that is reproduced. The speaker 931 outputs sounds of thenavigation function or the content that is reproduced.

The wireless communication interface 933 supports any cellularcommunication scheme such as LET and LTE-Advanced, and performs wirelesscommunication. The wireless communication interface 933 may typicallyinclude, for example, a BB processor 934 and an RF circuit 935. The BBprocessor 934 may perform, for example, encoding/decoding,modulating/demodulating, and multiplexing/demultiplexing, and performsvarious types of signal processing for wireless communication.Meanwhile, the RF circuit 935 may include, for example, a mixer, afilter, and an amplifier, and transmits and receives wireless signalsvia the antenna 937. The wireless communication interface 933 may be aone chip module having the BB processor 934 and the RF circuit 935integrated thereon. The wireless communication interface 933 may includethe multiple BB processors 934 and the multiple RF circuits 935, asillustrated in FIG. 436. Although FIG. 43 illustrates the example inwhich the wireless communication interface 933 includes the multiple BBprocessors 934 and the multiple RF circuits 935, the wirelesscommunication interface 933 may also include a single BB processor 934or a single RF circuit 935.

Furthermore, in addition to a cellular communication scheme, thewireless communication interface 933 may support another type ofwireless communication scheme such as a short-distance wirelesscommunication scheme, a near field communication scheme, and a wirelessLAN scheme. In that case, the wireless communication interface 933 mayinclude the BB processor 934 and the RF circuit 935 for each wirelesscommunication scheme.

Each of the antenna switches 936 switches connection destinations of theantennas 937 among multiple circuits (such as circuits for differentwireless communication schemes) included in the wireless communicationinterface 933.

Each of the antennas 937 includes a single or multiple antenna elements(such as multiple antenna elements included in an MIMO antenna), and isused for the wireless communication interface 933 to transmit andreceive wireless signals. The car navigation device 920 may include themultiple antennas 937, as illustrated in FIG. 43. Although FIG. 43illustrates the example in which the car navigation device 920 includesthe multiple antennas 937, the car navigation device 920 may alsoinclude a single antenna 937.

Furthermore, the car navigation device 920 may include the antenna 937for each wireless communication scheme. In that case, the antennaswitches 936 may be omitted from the configuration of the car navigationdevice 920.

The battery 938 supplies power to blocks of the car navigation device920 illustrated in FIG. 43 via feeder lines that are partially shown asdashed lines in the figure. The battery 938 accumulates power suppliedform the vehicle.

The car navigation device 920 shown in FIG. 43 may include functions asthe transmitting station 100. In the car navigation device 920, thewireless communication unit 110, the storage unit 120, and thecontroller 130 described with reference to FIG. 6 may be implemented bythe wireless communication interface 933. Alternatively, at least someof these constituent elements may be implemented by the processor 921.

Further, the car navigation device 920 shown in FIG. 43 may includefunctions as the receiving station 200. In the car navigation device920, the wireless communication unit 210, the storage unit 220, and thecontroller 230 described with reference to FIG. 7 may be implemented bythe wireless communication interface 933. Alternatively, at least someof these constituent elements may be implemented by the processor 921.

The car navigation device 920 shown in FIG. 43 may include functions asthe communication control device 300. In the car navigation device 920,the wireless communication unit 310, the storage unit 320, and thecontroller 330 described with reference to FIG. 8 may be implemented bythe wireless communication interface 933. Alternatively, at least someof these constituent elements may be implemented by the processor 921.

The technology of the present disclosure may also be realized as anin-vehicle system (or a vehicle) 940 including one or more blocks of thecar navigation device 920, the in-vehicle network 941, and a vehiclemodule 942. The vehicle module 942 generates vehicle data such asvehicle speed, engine speed, and trouble information, and outputs thegenerated data to the in-vehicle network 941.

6. CONCLUSION

Embodiments of the present disclosure have been described in detail withreference to FIGS. 1 to 43. As described above, the transmitting station100 that performs wireless communication with the receiving station 200using IDMA controls an interleave length in an interleave process forIDMA. Accordingly, the transmitting station 100 can perform theinterleave process with various interleave lengths to thereby facilitatea decoding process at a receiving side and improve decoding performance.

In addition, the transmitting station 100 according to the presentembodiment controls whether to perform wireless communication using IDMAon the basis of whether a transmission sequence is a retransmittedsequence or not. Furthermore, the transmitting station 100 controls atleast one of an interleave pattern and an interleave length depending onthe number of retransmissions or a retransmission process type (adaptiveor non-adaptive HARQ, CC or IR) when wireless communication using IDMAis performed. Accordingly, the transmitting station 100 can performvarious interleave processes depending on a retransmission state tothereby facilitate a decoding process at a receiving side and improvedecoding performance.

The preferred embodiment(s) of the present disclosure has/have beendescribed above with reference to the accompanying drawings, whilst thepresent disclosure is not limited to the above examples. A personskilled in the art may find various alterations and modifications withinthe scope of the appended claims, and it should be understood that theywill naturally come under the technical scope of the present disclosure.

The series of control processes carried out by each device described inthe present specification may be realized by software, hardware, or acombination of software and hardware. Programs that compose suchsoftware may be stored in advance for example on a storage medium(non-transitory medium) provided inside or outside each of the device.As one example, during execution, such programs are written into RAM(Random Access Memory) and executed by a processor such as a CPU.

Note that it is not necessary for the processing described in thisspecification with reference to the flowchart to be executed in theorder shown in the flowchart. Some processing steps may be performed inparallel. Further, some of additional steps can be adopted, or someprocessing steps can be omitted.

Further, the effects described in this specification are merelyillustrative or exemplified effects, and are not limitative. That is,with or in the place of the above effects, the technology according tothe present disclosure may achieve other effects that are clear to thoseskilled in the art based on the description of this specification.

Additionally, the present technology may also be configured as below.

(1)

A wireless communication device including:

a wireless communication unit that performs wireless communication usinginterleave division multiple access (IDMA) with another wirelesscommunication device; and

a controller that controls an interleave length in an interleave processfor IDMA by the wireless communication unit.

(2)

The wireless communication device according to (1), wherein thecontroller controls whether to perform wireless communication using IDMAdepending on whether a transmission sequence is a retransmitted sequenceor not.

(3)

The wireless communication device according to (2), wherein thecontroller controls the wireless communication unit to perform wirelesscommunication using IDMA when the transmission sequence is aretransmitted sequence.

(4)

The wireless communication device according to (2) or (3), wherein thecontroller controls the interleave length depending on a retransmissionprocess type.

(5)

The wireless communication device according to any one of (2) to (4),wherein the controller controls an interleave pattern in the interleaveprocess by the wireless communication unit.

(6)

The wireless communication device according to (5), wherein thecontroller controls the interleave pattern depending on the number ofretransmissions.

(7)

The wireless communication device according to (5) or (6), wherein thecontroller controls the interleave pattern depending on a retransmissionprocess type.

(8)

The wireless communication device according to any one of (2) to (7),wherein the controller controls whether to perform wirelesscommunication using IDMA depending on the number of wirelesscommunication devices that are retransmission targets.

(9)

The wireless communication device according to any one of (2) to (8),wherein the controller controls the wireless communication unit toemploy chase combining (CC) as a retransmission process type.

(10)

The wireless communication device according to any one of (1) to (9),wherein the controller controls the interleave length on the basis ofthe quantity of radio resources available for transmission by thewireless communication unit and a used modulation scheme.

(11)

The wireless communication device according to any one of (1) to (10),wherein the controller controls the wireless communication unit toperform padding when a length of an input sequence to the interleaveprocess does not reach the interleave length.

(12)

The wireless communication device according to (11), wherein thecontroller controls the wireless communication unit to perform paddingon the input sequence to the interleave process.

(13)

The wireless communication device according to (11), wherein thecontroller controls the wireless communication unit to perform paddingon an output sequence of the interleave process.

(14)

The wireless communication device according to any one of (1) to (13),wherein the wireless communication unit performs the interleave processhaving a sequence (codeword) obtained by connecting one or more errorcorrection code sequences (code blocks) as a target.

(15)

A wireless communication device including:

a wireless communication unit that performs wireless communication usingIDMA with another wireless communication device; and

a controller that controls the wireless communication unit to perform adeinterleave process depending on an interleave length used for aninterleave process for IDMA by the other wireless communication device.

(16)

A wireless communication method including:

performing wireless communication using IDMA with another wirelesscommunication device; and

controlling an interleave length in an interleave process for IDMAthrough a processor.

(17)

The wireless communication method according to (16), including

controlling wireless communication using IDMA to be performed when atransmission sequence is a retransmitted sequence.

(18)

A wireless communication method including:

performing wireless communication using IDMA with another wirelesscommunication device; and

controlling a deinterleave process depending on an interleave lengthused for an interleave process for IDMA by the other wirelesscommunication device to be performed through a processor.

A wireless communication method.

(19)

A program for causing a computer to function as:

a wireless communication unit that performs wireless communication usingIDMA with another wireless communication device; and

a controller that controls an interleave length in an interleave processfor IDMA by the wireless communication unit.

(20)

A program for causing a computer to function as:

a wireless communication unit that performs wireless communication usingIDMA with another wireless communication device; and

a controller that controls the wireless communication unit to perform adeinterleave process depending on an interleave length used for aninterleave process for IDMA by the other wireless communication device.

REFERENCE SIGNS LIST

-   1 wireless communication system 1-   100 transmitting station-   110 wireless communication unit-   111 CRC adding unit-   112 CB segmentation unit-   113 CRC adding unit-   114 FEC coding unit-   115 rate-matching unit-   116 CB connecting unit-   117 interleaver setting unit-   118 CW interleaver-   120 storage unit-   130 controller-   200 receiving station-   210 wireless communication unit-   211 channel estimator-   212 multiuser/multilayer detector-   213 CW deinterleaver-   214 CW decoder-   215 CRC decoder-   216 CW interleaver-   217 soft bit buffer-   218 PHY layer controller-   220 storage unit-   230 controller-   300 communication control device-   310 communication unit-   320 storage unit-   330 controller-   400 cell-   500 core network

1. A wireless communication device comprising: circuitry configured toperform wireless communication using an interleave process with anotherwireless communication device; and (i) determine a quantity of radioresources available for transmission by the wireless communicationdevice, (ii) determine a modulation scheme used for the wirelesscommunication performed by the wireless communication device, and (iii)control, in accordance with the determined quantity of radio resourcesand determined modulation scheme, an interleave length in the interleaveprocess performed by the wireless communication device.
 2. The wirelesscommunication device according to claim 1, wherein the circuitry isconfigured to control whether to perform wireless communication usingthe interleave process depending on whether a transmission sequence is aretransmitted sequence or not.
 3. The wireless communication deviceaccording to claim 2, wherein the circuitry is configured to performwireless communication using the interleave process when thetransmission sequence is a retransmitted sequence.
 4. The wirelesscommunication device according to claim 2, wherein the circuitry isconfigured to set the interleave length depending on a retransmissionprocess type.
 5. The wireless communication device according to claim 2,wherein the circuitry is configured to set an interleave pattern in theinterleave process.
 6. The wireless communication device according toclaim 5, wherein the circuitry is configured to set the interleavepattern depending on the number of retransmissions.
 7. The wirelesscommunication device according to claim 5, wherein the circuitry isconfigured to control the interleave pattern depending on aretransmission process type.
 8. The wireless communication deviceaccording to claim 2, wherein the circuitry is configured to controlwhether to perform wireless communication using the interleave processdepending on the number of wireless communication devices that areretransmission targets.
 9. The wireless communication device accordingto claim 2, wherein the circuitry is configured to employ chasecombining (CC) as a retransmission process type.
 10. The wirelesscommunication device according to claim 1, wherein the interleaveprocess is for interleave division multiple access (IDMA) with theanother wireless communication device.
 11. The wireless communicationdevice according to claim 1, wherein the circuitry is configured toperform padding when a length of an input sequence to the interleaveprocess does not reach the interleave length.
 12. The wirelesscommunication device according to claim 11, wherein the circuitryconfigured to perform padding on the input sequence to the interleaveprocess.
 13. The wireless communication device according to claim 11,wherein the circuitry configured to perform padding on an outputsequence of the interleave process.
 14. The wireless communicationdevice according to claim 1, wherein the circuitry configured to performthe interleave process with a sequence (codeword) obtained by connectingone or more error correction code sequences (code blocks) as a target.15. The wireless communication device according to claim 2, wherein thecircuitry is further configured to determine a retransmission processtype and controls the interleave length in accordance with thedetermined retransmission process type.
 16. A wireless communicationdevice comprising: circuitry configured to perform wirelesscommunication using an interleave process with another wirelesscommunication device; and control a deinterleave process depending on aninterleave length used for the interleave process performed by theanother wireless communication device, wherein the interleave length iscontrolled in accordance with a determined quantity of radio resourcesavailable for transmission by the another wireless communication deviceand a determined modulation scheme used for the transmission by theanother wireless communication device.
 17. A wireless communicationmethod comprising: performing, wireless communication using aninterleave process with another wireless communication device;determining, a quantity of radio resources available for performing thewireless communication; determining, a modulation scheme used for thewireless communication performed; and controlling, an interleave lengthin the interleave process.
 18. The wireless communication methodaccording to claim 17, further comprising: controlling wirelesscommunication using the interleave process to be performed when atransmission sequence is a retransmitted sequence.